Physiology of the male reproductive system.
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Adolescent↗
Biomedical subjects
T T Turner
Publications and source records attributed to T T Turner.
In vivo sodium, potassium, and sperm concentrations in the rat epididymis.
In vivo samples of epididymal fluids were obtained through the use of micropuncture techniques. Microsamples from four areas of the rat epididymis were analyzed for Na+ and K+ concentrations and for sperm density. Na+ values declined significantly from caput to corpus epididymidis (P less than 0.01), while K+ and sperm concentrations increased significantly (P less than 0.01). A large water loss from the epididymal lumen was calculated, as well as net losses of both cations. Water losses may be explained on the basis of an active Na+ pump; however, the effect of the absolute values of epididymal Na+ and K+ concentrations on sperm motility and fertility remains unresolved.
Animals↗
Hyperglycemia in the hamster anesthetized with Inactin [5-ethyl-5-(-methyl propyl)-2-thiobarbiturate].
Adult, male hamsters anesthetized with lnactin [5-ethyl-5-(1-methyl propyl)-2-thiobarbiturate] were found to be hyperglycemic. Blood glucose concentrations in anesthetized hamsters (300.1+/-15.6 mg/dl) were more than twice those of control animals (144.8+/-7.7 mg/dl). Neither the length of time under anesthesia nor the performance of surgery influenced the blood glucose concentration.
Anesthesia↗
The hormonal control of the guinea pig corpus luteum during early pregnancy.
Forty guinea pigs were divided into two groups, pregnant and nonpregnant, and were operated upon on days 10, 12, 14, and 16 of the ovarian cycle or of pregnancy. Blood was obtained from the utero-ovarian vein, and prostaglandin F2alpha (PGF2alpha), prostaglandin E (PGE), progesterone, and estrogen content was assayed by radioimmunoassay. Increased levels of PGF2alpha preceded a drop in progesterone levels in nonpregnant animals, reflecting luteolysis. In pregnant animals, the level of PGF2alpha remained low, and progesterone levels increased. PGE levels were similar in the two groups. These results suggest that the low PGF2alpha levels seen during early pregnancy are related to corpus luteum rescue.
Animals↗
Pattern and duration of ovum transport in the baboon (Papio anubis).
The normal pattern and duration of ovum transport was determined in a group of unmated, spontaneously ovulating baboons (Papio anubis) in which the time of ovulation had been determined directly using serial laparoscopy or indirectly using periovulatory estrogen values, perineal sex skin changes, and corpus luteum histology. At laparotomy, the reproductive tract was segmentally flushed at 24, 48, or 72 hours after ovulation and the position of the ova within the tract ascertained. Ova were consistently recovered from the ampulla 24 hours after ovulation, from both the ampulla and isthmus at 48 hours, and from the uterus 72 hours after ovulation. These results suggest that the baboon constitutes a potentially valuable animal model for the investigation and preclinical evaluation of contraceptive technics affecting tubal function.
Animals↗
Effect of epididymal isolation on the protein component of bull eididymal tissue.
Four fractions of protein from intact and 'isolated' bull epididymides were extracted. The total extractable protein was increased by isolation mainly due to increases in the lipoprotein and DNA-protein fractions. Changes of lipoprotein may be associated with the increase of lipid which also occurs in isolated tissue. This may reflect the increase of pentose cycle activity and lipogenesis due to the absence of spermatozoa in the epididymal tubules. Changes of DNA-protein may indicate a change of protein metabolism. Electrophoresis of protein fractions showed that individual proteins may be changed by the zonal origin of the epididymal tissue and the presence or absence of spermatozoa in the epididymal tubules.
Animals↗
The metabolic activity of the bovine epididymis. I. Utilization of glucose and fructose.
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Animals↗
Fatty acid relationships of the normal and efferentiectomized bovine epididymis.
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Animals↗
The metabolic activity of the bovine epididymis. II. Utilization of acetate, succinate, pyruvate, lactate and glucose.
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Acetates↗
The ability of the rat epididymis to concentrate spermatozoa. Responsiveness to aldosterone.
Experiments have been performed to determine if aldosterone is involved in the control of water reabsorption from the epididymal lumen in vivo. Micropuncture samples of lumen content were collected from the epididymides of control rats and those receiving aldrenalectomy, adrenalectomy + 25 micrograms aldosterone/day, 10 mg spironolactone/kg body weight/day, 10 mg spironolactone + 1 mg testosterone/kg body weight/day, 5 mg desoxycorticosterone acetate (DOCA)/day, 50 micrograms aldosterone/day, or 0.1 ml vehicle alone. The treatment period was three days. Seminal vesicles weights and testis weights were obtained. Sperm concentrations (SEM) in the caput, corpus, and cauda epididymidis of normal rats were 0.75 +/- 0.05, 1.24 +/- 0.13, and 1.99 +/- 0.15 x 10(9) sperm/ml, respectively. Both inhibition and removal of aldosterone caused significant reduction (P less than .01) of intraluminal sperm concentrations. Sham treatment had no effect. Sperm concentrations were normal in animals receiving aldrenalectomy plus aldosterone replacement. It is concluded that water resorption in the rat epididymis is responsive to aldosterone.
Adrenalectomy↗
Acute experimental testicular torsion. No effect on the contralateral testis.
Other investigators have shown that chronic unilateral testicular torsion produces negative effects on the contralateral testis in experimental animals. In the present study, bilateral testicular weight and histology, and concentrations and motility of spermatozoa from the cauda epididymidis were studied after 0 to 4 hours of acute unilateral testicular torsion in the rat. The obstruction of blood flow by torsion was documented, as well as the presence or absence of return blood flow after the relief of torsion. The above mentioned parameters of testicular function were studied at 7, 30, and 60 days after relief of torsion. Ipsilateral testis weights and epididymal sperm concentrations and motility were significantly reduced by 1, 2, and 4 hours of torsion. The histology of torsioned testes was also severely altered, and no seminiferous epithelial repair was evident 60 days after torsion. Contralateral testicles were not affected by ipsilateral torsion of 1, 2, or 4 hours duration, despite the fact that the ipsilateral testis function was completely compromised by 2 and 4 hours of torsion. These results indicate that there would be no clinical benefit in removing the acutely torsioned testis of Sprague-Dawley rats since it poses no threat to the contralateral testis.
Acute Disease↗
Androgens in various fluid compartments of the rat testis and epididymis after hypophysectomy and gonadotropin supplementation.
Hypophysectomized male rats were administered LH or LH + FSH for 14 days and subjected to in vivo micropuncture collection of reproductive tract fluids to determine if FSH alters the compartmentalization of testosterone in the rat testis or of 5 alpha-dihydrotestosterone (DHT) in the epididymis. Testosterone and DHT concentrations were determined in cardiac blood serum, testicular venous serum, testicular interstitial fluid, and seminiferous tubule fluid, and in intraluminal fluid and tissue extracts from the caput and cauda epididymidis. Testosterone is the predominant androgen in the testis, and compared with control values, concentrations in venous sera, interstitial fluid, and tubule fluid were returned to values indistinguishable from controls by supplementation with 24 micrograms LH/day. 24 micrograms LH + 24 micrograms FSH/day did not augment the intratubular partition of testosterone. Epididymal DHT values were returned to control levels by LH alone, but additional supplementation with FSH significantly increased DHT from the caput epididymidis even further. It is speculated that FSH does not alter the compartmentalization of androgens in the rat testis, but may play a role in retaining androgens in the epididymis.
Androgens↗
The heterogeneity of rat androgen binding protein (rABP) in the vascular compartment differs from that in the testicular tubular lumen. Further evidence for bidirectional secretion of rABP.
Fractionation of testicular extracts and serum on a Concanavalin A-Sepharose column resolved two peaks of immunoreactive rat androgen binding protein. The rat androgen binding protein in the first peak, designated Form I, was present in the void volume; the other, designated Form II rat androgen binding protein, was bound by the column and specifically eluted by alpha-methylmannoside. In the course of studying the heterogeneity of rat androgen binding protein on Concanavalin A-Sepharose, it was observed that the distribution of the two forms of this protein was similar in the fluid obtained by micropuncture from the seminiferous tubule and the rete testis, that is, the ratios of Form I to Form II were 1:1 and 1:1.8, respectively. By contrast, Form I rat androgen binding protein in blood, interstitial fluid, and thoracic duct lymph of adult rats was reduced relative to Form II; the ratios of Form I:Form II in these fluids were 1:4.4, 1:3.1, and 1:4.6, respectively. since previous studies indicated that the reduced amount of Form I relative to Form II observed in the blood of adult rats was not the result of more rapid clearance of Form I, these results suggest that Form I rat androgen binding protein is preferentially secreted into the lumen of the seminiferous tubule rather than into the interstitial fluid and blood. We conclude that Sertoli cells in adult rats may partition rat androgen binding protein between the interstitial and luminal compartments of the testis based on the carbohydrate composition of this protein.
Androgen-Binding Protein↗
Repair of experimental varicoceles in the rat. Long-term effects on testicular blood flow and temperature and cauda epididymidal sperm concentration and motility.
The effects of varicocele and varicocele repair on testicular blood flow, temperature, sperm counts, and sperm motility were assessed in adult male rats. The duration of the experimental varicocele and the varicocele repair were three and two times as long, respectively, as that studied previously. Varicoceles were created by partial ligation of the left renal vein and repairs were accomplished by high ligation of the left spermatic vein. Testicular blood flow was determined by using the radiolabeled microsphere technique. Testicular temperature was taken via needle probe thermometer. Sperm samples were obtained by micropuncture of the cauda epididymidis, and were counted on a hemacytometer and observed for motility under the light microscope. Varicoceles were studied 100 days after their creation. Repairs were performed on varicoceles that had lasted 100 days and the animals were studied 60 days after repair. Mean testicular blood flow (ml/100 g tissue/min) was significantly increased (P less than 0.05) in animals with varicocele (left testis (LT) = 42.2 +/- 1.1, right testis (RT) = 39.1 +/- 1.2) when compared with normal controls (LT = 29.3 +/- 1.6, RT = 29.6 +/- 1.7), animals with varicocele repair (LT = 30.7 +/- 1.3, RT = 30.0 +/- 1.6), or sham-operated animals (LT = 29.7 +/- 1.4, RT = 31.1 +/- 1.4).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
The effects of unilateral, experimental varicocele are not mediated through the ipsilateral testis.
Unilateral varicocele has been associated with diminished male fertility in humans and with bilateral physiologic and histologic changes in the testis of humans and laboratory animals. In particular, left varicocele in Sprague-Dawley rats results in bilateral increases in testicular temperature and blood flow. The mechanism by which unilateral varicocele can cause testicular changes is not known. The purpose of the present study was to determine whether or not the presence of either the ipsilateral or contralateral testicle is necessary for these effects of the varicocele to occur in the opposite testis. Varicoceles were created in adult, male rats by partial constriction of the left renal vein. Bilateral testicular blood flow was measured by a radiolabelled microsphere distribution technique and testicular temperature was taken with a needle probe thermometer. Right or left orchiectomies were performed on selected animals at the time of surgery to establish the unilateral left varicocele. Animals were studied 30 days after surgery. Mean testicular blood flow was significantly increased (P less than 0.01) in all animals having a left varicocele when compared with animals not having a varicocele regardless of whether a unilateral orchiectomy was performed. Likewise, the mean difference between intraabdominal temperature and intratesticular temperature (delta T) was significantly decreased in all groups of animals having varicoceles when compared with groups without varicoceles whether or not an orchiectomy had been performed. Thus, the studied bilateral effects of left-sided, experimental varicocele in the rat are not dependent upon the presence of a left testicle.
Animals↗
Luteinizing hormone secretion by male rat pituitary cells perifused in vitro: effect of experimental left varicocele and orchiectomy.
It has been shown previously that experimental left varicocele in the rat, results in a bilateral decrease in intratesticular testosterone. In the present work, pituitary responsiveness to GnRH as a possible mediator of this effect has been examined. Unilateral varicoceles were created in adult rats. A second group of animals underwent a sham operation and a third underwent bilateral orchiectomy. Thirty days after surgery, rats from all three groups were sacrificed and their pituitaries were removed. Dispersed pituitary cells were perifused in Bio-Gel columns with varying concentrations of GnRH. The concentration of LH in the collected eluent was determined by radioimmunoassay. The mean, overall GnRH-stimulated LH immunoreactive secretion rate (ng/min/10(7) cells) by pituitary cells from rats with varicocele (0.062 +/- 0.11) was no different from the overall release from the sham-operated controls (0.051 +/- 0.007). The dose-response curves for GnRH-stimulated release of LH by dispersed pituitary cells in the two groups also were not different. The overall GnRH-stimulated LH release by cells from the orchiectomized rats (0.171 +/- 0.032) was significantly greater than release by cells from the sham-operated and varicocele rats, and the concentration-response curve from the orchiectomy group was significantly elevated over those of the other two groups. These results indicate that GnRH-stimulated immunoreactive LH release is not altered in rats with experimental left varicocele and, thus, is not the source of an endocrinopathy that leads to decreased intratesticular testosterone concentrations in these animals.
Animals↗
The study of varicocele through the use of animal models.
The pathophysiology of the varicocele has received considerable study, both in humans and in animal models. Mechanistic information is difficult to obtain from human subjects because study designs must not be invasive and the subject population is variable in the status of the varicocele, patient age, fertility or other health-related issues. Because of these limitations, animal models of varicocele have been developed in several species, the most common being the rat. Surgery to establish the varicocele involves partial obstruction of the left renal vein, causing a varicosity of the left spermatic vein, including the pampiniform plexus. Studies using this model have shown that experimental left varicocele induces bilateral increases in testicular blood flow and temperature contemporaneous with decreases in intratesticular testosterone and testicular sperm output. Spermatic vein reflux is not related to the pathophysiological consequences of experimental varicocele. Many questions remain regarding the mechanism by which varicocele induces testicular dysfunction, chief among them being how the unilateral varicocele causes a bilateral testicular response in the first place.
Animals↗
Obstruction of the vas deferens alters protein secretion by the rat caput epididymidal epithelium in vivo.
Obstruction of epididymal lumen fluid flow alters the intraluminal environment and potentially changes epididymal epithelial cell function when those functions are dependent on intraluminal regulatory molecules. This investigation tested the hypothesis that obstruction of the rat vas deferens alters caput epididymidal protein synthesis and secretion In vivo. Adult male rats were subjected to vasal obstruction or sham operation. Fourteen days later, caput epididymides were subjected to in vivo microperfusion with medium containing a [35S]-amino acid mixture. At the end of a 3-hour perifusion, micropuncture was used to obtain caput lumen fluid (LF). Tubule extract (TE) was obtained as supernatant after homogenization and centrifugation of caput tubules. Tubule extract contained all [35S]-proteins synthesized within the 3-hour experiment, and LF contained the secreted [35S]-proteins. Radioactivity of trichloroacetic acid (TCA)-precipitable proteins in LF and TE was determined, and two-dimensional electrophoresis and autoradiography of each sample were carried out. The resultant autoradiograms were evaluated densitometrically. A protein synthesis index calculated from the TCA-precipitable radioactivity data demonstrated that a significant decline in overall protein synthesis was induced by vasal obstruction. Densitometry of autoradiograms demonstrated that the total number of radiolabeled proteins detected in both the LF and TE of obstructed animals was significantly smaller than the same number in control animals (P < 0.05). Autoradiography revealed seven major, consistently appearing gene products in LF, and these were subjected to amino acid sequence analysis. Cysteine-rich secretory protein (CRISP)-1 proteins were significantly reduced in the LF of obstructed animals, which implies that these proteins are dependent on luminal regulatory molecules for their normal production.
Amino Acid Sequence↗