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J Arunakaran

Publications and source records attributed to J Arunakaran.

54 records · Page 3Linked to original sources
PubMed1993

Effects of prolactin and androgens on enzymes of carbohydrate metabolism in seminal vesicles of castrated mature bonnet monkeys, Macaca radiata.

Effects of prolactin(Prl), bromocriptine(Br), testosterone propionate (TP), dihydrotestosterone (DHT) and combinations of these androgens with Prl/Br on the maximum catalytic capacities of seminal vesicular enzymes involved in the glycolytic and pentose phosphate pathways in castrated mature monkeys were studied. Castration decreased the activities of all of the enzymes studied such as hexokinase(HK), 6-phosphofructokinase(PFK), glyceraldehyde-3-phosphate dehydrogenase(G3PD), pyruvate kinase(PK), glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase(6PGD) in the seminal vesicles. Prl restored the activities of all of the enzymes to their normal values except G3PD. TP/DHT maintained all the enzyme activities at the normal tissue intact level. Prl given along with androgens further enhanced the androgen action with regard to all the enzymes activities except G3PD. Br decreased all of the enzymes but Br with androgens maintained all the enzyme activities at the normal level. Castration decreased significantly serum T/DHT titres but Prl did not alter Prl levels. Prl+TP/DHT elevated Prl levels. Br alone decreased serum Prl, T and DHT titres, but Br+TP/DHT decreased only Prl, elevated T and maintained DHT levels. These results suggest that Prl has a direct as well as a synergistic action with androgens on the activities of the enzymes of glycolysis and pentose phosphate pathways in the seminal vesicles of castrated monkeys.

Androgens↗
PubMed1992

Role of prolactin on epididymal glycoprotein metabolism in matured monkeys, Macaca radiata: specific activities of glycosyltransferases and glycosidases.

Impact of altered serum prolactin status on enzymes involved in glycoprotein metabolism in epididymal tissue of matured monkeys was studied. Hyperprolactinemia (ovine prolactin-250 micrograms/kg body weight/day for 30 days) significantly inhibited the specific activities of dolichylphosphate mannosyl transferase, dolichylphosphate glucosyl transferase and galactosyl transferase, in the epididymal tissues. However, it had an enhanced effect on epididymal glycosidases such as beta-galactosidase, beta-N-acetyl glucosaminidase, beta-N-acetyl galactosaminidase, alpha-mannosidase and alpha-L-fucosidase. Hypoprolactinemia (bromocriptine mesylate-1-mg/kg body weight/day for 30 days) on other hand had no significant effect on the specific activities of both, glycosyltransferases and glycosidases, in the epididymal tissues. The results suggest that hyperprolactinemia inhibits epididymal glycoprotein metabolism by impairing the incorporation of oligosaccharide units into proteins with enhanced degradation. This may have adverse effect on events leading to sperm maturation in epididymal environment.

Animals↗
PubMed1992

Effects of prolactin and androgens on enzymes of carbohydrate metabolism in prostate of castrated bonnet monkeys Macaca radiata (Geoffroy).

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combinations of these androgens with PRL/Br on the specific activities of caudal and cranial prostatic cellular enzymes involved in carbohydrate metabolism in castrated mature bonnet monkeys have been studied. Castration decreased all the enzymes studied such as hexokinase (HK), 6-phosphofructokinase (6-PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PD), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phosphogluconate dehydrogenase (6-PGD) in the cranial and caudal prostates. PRL elevated the activities of all the enzymes above normal except G-3-PD of cranial lobe. In the caudal lobe, PRL brought back the activities of HK, PFK, PK, G-6-PD to normal and 6-PGD above normal except G-3-PD. TP/DHT treatment increased all the enzymes in both the lobes. PRL given along with TP/DHT further enhanced the androgen action with regard to HK, PK, G-6-PD and 6-PGD of cranial and PFK, G-3-PD, PK, G-6-PD and 6-PGD of caudal lobe. Br treatment did not produce any alteration of these enzymes in both the lobes. In the cranial lobe, during Br+TP/DHT treatment, the stimulating effects of androgen were unaffected on all the enzymes except PK. On the other hand in the caudal, the stimulatory effects of androgens were affected and the activities of HK, PFK, PK and 6-PGD were significantly decreased. The present results suggest that PRL has a direct as well as a synergistic action with androgens on enzymes of EMP and HMP shunt in the prostates of monkeys.

Androgens↗
PubMed1992

Interaction of androgens and prolactin on prostatic enzymes of the pyruvate-malate cycle involved in lipogenesis in castrated mature monkey, Macaca radiata.

Effects of androgens, prolactin (Prl) and bromocriptine (Br) on the specific activities of prostatic (caudal and cranial) enzymes of the pyruvate-malate cycle were studied in castrated mature bonnet monkeys. Castration decreased the activity of NADP+ isocitrate dehydrogenase (ICDH), ATP citrate lyase, malate dehydrogenase (MDH), malic enzyme and fatty acid synthase (FAS). Administration of testosterone propionate (TP)/dihydrotestosterone (DHT) increased the activities of all these enzymes in both lobes. Malate dehydrogenase maintained normal activity. Prl also had a stimulatory effect on the enzymes and was further enhanced when Prl was given in combination with TP/DHT. Unlike Prl, bromocriptine treatment inhibited all the enzymes in both lobes. Thus, prolactin was found to have a direct as well as a synergistic effect with androgens on enzymes of the pyruvate-malate cycle in the prostate of castrated mature monkeys.

ATP Citrate (pro-S)-Lyase↗
PubMed1990

Effects of prolactin and androgens on the prostatic lipids of castrated mature bonnet monkeys.

The effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT), and the combinations of these androgens with PRL/Br on total lipid, total cholesterol, total glyceride glycerols, and total phospholipid and their fractions in cranial and caudal prostates of castrated mature monkeys were studied. Glyceride glycerols formed the major portion of total lipids (50%) in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed the major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes in both the lobes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols in both the lobes. Phosphatidyl inositol, choline, and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal in both the lobes. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine, and phosphatidic acid in both the lobes. Br counteracted the effects of androgens and prolactin. In general, the influence of prolactin was more in the caudal lobe than cranial. The results are discussed in detail with available literature.

Animals↗
PubMed1990

Influence of prolactin, androgens and bromocriptine on seminal vesicular and prostatic adenosine triphosphatases in castrated adult monkeys Macaca radiata.

E ects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combinations of these androgens with PRL/Br on specific activities of adenosine triphosphatases (ATPases) of seminal vesicles and cranial and caudal prostates were studied in castrated adult bonnet monkeys. Castration decreased all ATPases (sodium/potassium, magnesium and calcium dependent) of seminal vesicles and both the lobes of prostate. PRL restored the normal activities of all ATPases in both the organs. Br given alone decreased all ATPases of prostate but caused no significant alteration, particularly calcium dependent ATPases of seminal vesicles and caudal prostate. TP/DHT replacement restored all ATPases of both the organs to the normal levels. PRL + TP/DHT further enhanced all the ATPases activities of all the regions studied. Br + TP/DHT decreased all ATPases but it did not produce any alteration in the calcium ATPases of seminal vesicles. The results suggest that prolactin facilitates membrane transport enzymes in the cranial and caudal prostate and seminal vesicles of adult castrated bonnet monkeys.

Adenosine Triphosphatases↗
PubMed1989

Effect of corticosterone on epididymal lipids in pubertal rat.

Serum corticosterone excess was induced by the administration of corticosterone acetate to adrenal intact rats. Different lipid classes were studied in unwashed and washed (epididymal sperm and fluid free) caput and cauda epididymides. The unwashed caput epididymidis registered a significant decrease in total lipid, cholesterol and phospholipid while total glyceride glycerol and its fractions were not altered after corticosterone treatment. Among phospholipid fractions phosphatidyl inositol, choline and ethanolamine showed a significant decrease. Unlike the unwashed caput epididymidis, the washed caput region recorded a marked increase in total lipid, glyceride glycerol and its fractions. However, total lipid in the washed cauda region significantly increased and the increase was mainly due to triacyl glycerol. Though the phospholipid fractions phosphatidyl choline and ethanolamine showed an increase, the total phospholipid was not altered significantly. Serum testosterone and prolactin registered a significant decrease while gonadotropins were unaltered. On the withdrawal of corticosterone treatment, all the lipid classes turned to normalcy along with serum testosterone and prolactin. It is concluded that corticosterone excess favours lipid accumulation in the sperm free epididymal tissue and its influence on epididymis is region specific and reversible.

Animals↗
PubMed1989

Effects of prolactin and androgens on seminal vesicular lipids of castrated mature bonnet monkeys Macaca radiata.

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combination of these androgens with PRL/Br on the total lipid, total cholesterol, total glyceride glycerols, total phospholipid and their fractions in seminal vesicles of castrated mature monkeys were studied. Glyceride glycerols formed the major portion (50%) of total lipids in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols. Phosphatidyl inositol, choline and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine and phosphatidic acid. In all these aspects, Br counteracted the effects of androgens and PRL.

Animals↗
PubMed1988

Effects of androgens, prolactin and bromocriptine on seminal vesicular enzymes of the pyruvate malate cycle involved in lipogenesis in castrated mature monkeys, Macaca radiata.

The interaction of androgens and prolactin, the major factors regulating the male accessory sex organs, on the specific activity of seminal vesicular enzymes of the pyruvate/malate cycle were studied in castrated mature monkeys. Castration decreased the activity of these enzymes, including NADP+ isocitrate dehydrogenase, ATP citrate lyase, malate dehydrogenase, malic enzyme and fatty acid synthase. Testosterone propionate (TP)/dihydrotestosterone given as replacement to castrates increased the activity of all these enzymes, except for malate dehydrogenase. Prolactin restored normal activity of ATP citrate lyase, malic enzyme and fatty acid synthase but not of isocitrate dehydrogenase and malate dehydrogenase (MDH). Prolactin had a specific control over MDH. Moreover, when prolactin was combined with androgens a further stimulatory influence was observed on fatty acid synthase activity. In order to prove the direct influence of prolactin on enzymes of the pyruvate/malate cycle, bromocriptine was administered and this inhibited all of the enzymes. Thus prolactin was found to have a direct, as well as a synergistic, action with androgens on enzymes of the pyruvate/malate cycle in the seminal vesicles of monkeys.

ATP Citrate (pro-S)-Lyase↗
PubMed1987

Effect of prolactin and androgens on the prostate of bonnet monkeys, Macaca radiata: I. Nucleic acids, phosphatases, and citric acid.

The effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT), and the combinations of these androgens with PRL/Br on the growth and secretory activities of cranial and caudal prostates were studied in castrated mature monkeys, Macaca radiata. Castration decreased the body weight, organ weights, nucleic acids (DNA and RNA), phosphatases, and citric acid of cranial and caudal prostates. PRL did not alter the body weight but increased the organ weights, nucleic acids, phosphatase activities, and citric acid. Br given alone decreased the body weight and the secretory activities of prostates but caused no significant alteration in the nucleic acids. TP/DHT replacement brought back the body weight and prostatic nucleic acids to normal. It enhanced the weights, phosphatase activities, and citric acid contents of cranial and caudal prostates. PRL + TP/DHT enhanced the body weight, organ weight, and secretory activities. Br + TP/DHT decreased the body weight and secretory products of prostate but it did not produce any alteration in the organ weight and RNA content. These results suggest that PRL plays a specific stimulatory influence on monkey prostate.

Androgens↗
PubMedDate not supplied

Antiproliferative effect of diallyl disulfide (DADS) on prostate cancer cell line LNCaP.

Garlic has been used throughout the world to treat coughs, toothache, earache, dandruff, hypertension, hysteria, diarrhoea, dysentery, diptheria, vaginitis and many other conditions. Garlic contains a complex mixture of oil and water-soluble organosulfur compounds. Diallyl disulfide (DADS), an oil-soluble constituent of garlic seems to be effective in reducing tumour cells originating from colon, lung and skin. Hence our present study focuses on the dose-dependent effect of DADS on an androgen-dependent prostate cancer cell line. Various concentrations of DADS ranging from 25 to 100 microM were given to LNCaP cells and the activity of lactate dehydrogenase (LDH) prostatic acid phosphatase (PAcP) and the level of prostate specific antigen were studied. DADS reduced the secretory activity of LNCaP cells with the gradual increase in dosage. DADS was found to act as a good antiproliferative agent, which was confirmed by proliferation assay. DADS also induced apoptosis and nuclear segmentation in the higher doses.

Acid Phosphatase↗
PubMedDate not supplied

Interactions of androgens and prolactin in the seminal vesicles of mature bonnet monkeys, Macaca radiata. I. Nucleic acids and phosphatases.

The effects of prolactin (PRL), bromocriptine, testosterone propionate (TP), dihydrotestosterone (DHT), and the combinations of these androgens with PRL or bromocriptine on nucleic acids (RNA and DNA) and phosphomonoesterases (acid and alkaline phosphatase) of the seminal vesicles of castrated mature bonnet monkeys were studied. Castration decreased body weight, and seminal vesicle organ weight, nucleic acids and acid and alkaline phosphatases. TP/DHT replacement to castrates restored body weights and seminal vesicle DNA to normal and markedly increased the weight, RNA content and acid and alkaline phosphatase activities of the seminal vesicles. PRL did not alter body weight and increased the weight of the seminal vesicles, and their RNA content and phosphomonoesterase activities. PRL + TP/DHT enhanced all parameters. Bromocriptine given alone decreased body weight and acid phosphatase. Bromocriptine given along with TP/DHT suppressed the stimulatory influence of these androgens on most of the parameters studied. The results of the present study suggest that PRL has a specific stimulatory effect on seminal vesicle growth and function, that the presence of PRL is essential for androgen action, and that PRL acts synergistically with androgens.

Acid Phosphatase↗
PubMedDate not supplied

Impact of neonatal onset hypothyroidism on Sertoli cell number, plasma and testicular interstitial fluid androgen binding protein concentration.

The impact of neonatal onset hypothyroidism from day 1 postpartum through different postnatal developmental events on rat testis was studied in vivo. Hypothyroidism was induced in neonates by feeding the lactating mother or directly with 0.05% methimazole (MMI) through drinking water from the day of birth and were killed at day 10, 15, 30, 40 and 60 postpartum. Hypothyroidism was confirmed by radioimmunoassay of thyroid hormones and TSH. Sertoli cell number, plasma and testicular interstitial fluid (TIF) androgen binding protein (ABP) concentration was quantified. Sertoli cell number was consistently decreased in all hypothyroid rats. Plasma ABP was also decreased irrespective of the duration of hypothyroidism. Unlike plasma ABP, TIF ABP concentration in hypothyroid rats increased at day 10, and 15 postpartum and decreased in other age groups. Plasma FSH level was increased significantly in all hypothyroid groups. The present investigation points out that suppression of T3 during the critical period of Sertoli cell proliferation affects their number and functional activity.

Aging↗
PubMedDate not supplied

Duration-dependent effect of transient neonatal hypothyroidism on sertoli and germ cell number, and plasma and testicular interstitial fluid androgen binding protein concentration.

The impact of transient neonatal hypothyroidism on growth and function of puberal testis during different milestones of postnatal testicular development was studied in Wistar rats. Rat pups were made hypothyroid for 10, 15, 30, 40 and 60 days of postnatal age from birth by providing 0.05% (W/V) methimazole (MMI) in the drinking water of the mother, from day 1 postpartum till weaning (25 days postpartum) and thereafter in the drinking water. Control rats were raised without MMI treatment. Sertoli cell number and its function was assessed on day 60 postpartum. Sertoli cell number increased consistently in 10, 15, 30 and 40 days transient hypothyroid rats but decreased in rats subjected to continuous hypothyroidism from birth to 60 days postpartum. Rats subjected to continuous hypothyroidism from birth showed spermatogenic arrest at puberty and had only a single layer of spermatogonia. Transient neonatal hypothyroidism for 10 (or) 15 days from birth increased spermatocytes (pachytene and zygotene), spermatids (elongated and round) whereas, that of 30 and 40 days decreases the number of germ cells. Plasma androgen binding protein (ABP) concentration decreased in puberal rats belonging to all groups, whereas the testicular interstitial fluid (TIF) concentration of ABP increased significantly in 10 and 15 days hypothyroid rats while it decreased in all other groups. These findings indicate that the mitogenic activity of Sertoli cell is increased irrespective of the duration of transient neonatal hypothyroidism. However, the functional activity of Sertoli cells (ABP production) in these puberal rats varies depending upon the postnatal period at which the animals were in hypothyroid state.

Aging↗
PubMedDate not supplied

Impact of neonatal hypothyroidism on Leydig cell number, plasma, and testicular interstitial fluid sex steroids concentration.

We have previously demonstrated that neonatal and transient neonatal hypothyroidism modulates Leydig, Sertoli, and germ cell numbers, sex steroids and androgen binding protein concentration. The present study was undertaken to study the effect of neonatal onset hypothyroidism on Leydig and peritubular myoid cell numbers, plasma and testicular interstitial fluid (TIF) sex steroid concentration at different age groups of Wistar rats. Hypothyroidism was induced by giving 0.05% methimazole (MMI) to lactating mothers or directly to the male pups from day 1 postpartum through days 10, 15, 30, 40 and 60 postpartum. To confirm hypothyroidism, plasma thyroid hormones and TSH were assayed. Plasma and TIF testosterone, progesterone, dihydrotestosterone (DHT) and estradiol were assayed by radioimmunoassay. Leydig cell number in hypothyroid rats were less than the age-matched controls. The diameter of Leydig cells in hypothyroid rats was smaller than the controls but 10 days old hypothyroids alone had larger than control rats. A significant decrease of peritubular myoid cell number was observed in 30, 40 and 60 days hypothyroid rats and increased in 10 and 15 days hypothyroidism. Hypothyroid rats had elevated level of plasma LH and decreased GH (except day 10 postpartum). Plasma PRL level was increased in 10 and 15 days hypothyroid rats and an opposite effect was observed in 40 and 60 days hypothyroidism. Plasma testosterone, DHT and estradiol were decreased in all hypothyroid rats. However, plasma progesterone level in hypothyroid rats was significantly higher at days 10, 30, and 40 postpartum and an opposite effect was seen in 15 and 60 days experimental groups. TIF testosterone and progesterone titre showed a consistent decrease in hypothyroid rats irrespective of the duration. In hypothyroid rats, TIF DHT levels decreased significantly in days 10, 40 and 60 postpartum. However, it increased in days 15 and 30 postpartum. Except at day 10 postpartum, the level of TIF estradiol in hypothyroid rats was significantly less than their age matched controls. Our data clearly indicate that neonatal onset hypothyroidism adversely affect Leydig cell proliferation along with impaired steroidogenesis.

Aging↗
PubMedDate not supplied

Prostate-thyroid axis: prostatic TRH is one of the stimulators of thyroid hormone.

Ventral prostatectomy decreased serum thyroid hormones and histology of the thyroid gland indicate that hypothyroid condition. Co-culture of thyroid gland and ventral prostate stimulates thyroid hormone secretion. In the present study we report prostatic thyrotropin releasing hormone (TRH) is the stimulating factor of thyroid hormone secretion. Mature rat (90 days old) ventral prostate, anterior pituitary and thyroid glands were co-cultured in vitro with or without TRH antibody to assess the direct influence ofprostatic TRH on thyroid hormone secretion. Total thyroxine (T4) and triiodothyronine (T3) were increased significantly in the culture media of ventral prostate, anterior pituitary and thyroid gland when compared with thyroid gland plus anterior pituitary culture media. However, media T4 and T3 concentration decreased significantly in thyroid gland alone; also in thyroid gland plus ventral prostate, thyroid gland plus anterior pituitary and thyroid gland plus anterior pituitary plus ventral prostate were co-cultured with TRH antibody (Ab) in a dose dependent manner. The results suggest that ventral prostatic TRH is one ofthe stimulating factors of thyroid hormone secretion under these in vitro conditions.

Animals↗
PubMedDate not supplied

Influence of castration and testosterone propionate on prostatic and seminal vesicular lipids in mature monkeys.

The effect of castration and administration of testosterone propionate (TP) has been studied in mature monkeys in relation to prostatic and seminal vesicular lipids to castrates on prostatic and seminal vesicular lipids were studied in mature monkeys. Castration decreased prostatic total lipid, total phospholipids and total glyceride glycerols. Among neutral lipid classes only diacyl glycerol was decreased due to castration. Similarly among phospholipid classes, phosphatidyl choline and ethanolamine were decreased. A marked decrease in the seminal vesicular total lipid, total phospholipids, total cholesterol and total glyceride glycerol were observed due to castration. Mono and diacyl glycerols and phosphatidyl choline and ethanolamine also registered a significant decrease after castration. Administration of TP to castrates brought back all the lipid classes to normal level which showed a decrease due to castration. However, TP treated to castrates on both seminal vesicles and prostates had no effect on other classes of lipids which were unaltered by castration. The present study reveals that lipid metabolism in the male accessory sex organs is under androgenic control. Nevertheless, the influence of testicular androgen is specific to different classes of lipids as a number of phospholipids and neutral lipid classes were resistant to castration or administration of TP.

Animals↗