Brain aging and neuronal plasticity.
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Aging↗
Biomedical subjects
C Carani
Publications and source records attributed to C Carani.
Isolated adrenocorticotropic hormone deficiency secondary to hypothalamic deficit of corticotropin releasing hormone.
A 42-year-old man and a 51-year-old woman with a positive history of weakness and gastrointestinal complaints were shown to have low basal plasma cortisol and ACTH levels, and low daily urinary excretion of free cortisol. An empty sella was found in patient no. 1, while patient no. 2 was hypothyroid. Both patients showed a normal plasma cortisol response to ACTH and an increment in plasma ACTH and lipotropin levels after ovine CRH (oCRH), lysine vasopressin (LVP) and oCRH-LVP stimulation tests. These studies clearly report an isolated idiopathic ACTH deficiency due to a deficit in CRH in two adult subjects.
Adrenal Glands↗
Testosterone and erectile function, nocturnal penile tumescence and rigidity, and erectile response to visual erotic stimuli in hypogonadal and eugonadal men.
Further evidence that nocturnal erections are androgen-dependent and erectile responses to visual erotic stimuli are androgen-independent is presented from six men with secondary hypogonadism and six eugonadal controls. Erections during sleep were substantially less in the hypogonadal men, in terms of both tumescence and rigidity. In response to visual erotic stimuli, the percentage increase in circumference over baseline and the increase in rigidity were similar for the two groups.
Adult↗
Intramembrane interactions between neurotensin receptors and dopamine D2 receptors as a major mechanism for the neuroleptic-like action of neurotensin.
Evidence has been presented that behavioral actions of NT, inducing its neuroleptic-like action, can be explained on the basis of NT-D2 intramembrane receptor-receptor interactions in the basal ganglia, unrelated to the coexistence phenomenon, leading to reduced affinity and transduction of the D2 agonist binding site. By reducing selectively D2 receptor transduction at the pre- and postsynaptic level, the NT receptor appears capable of switching the DA synapses towards a D1 receptor-mediated transduction, illustrating how receptor-receptor interactions can increase the functional plasticity of central synapses (FIG. 12).
Animals↗
Sexual dimorphism of the autonomic nervous system response to weight loss in obese patients.
The sex-related response of the sympathoadrenal system to very low calorie diet (VLCD) with sodium restriction has been studied in a group of 16 obese subjects (8 men; 8 women). Once in sodium balance obese men were different from women in respect to initial body weight, mean daily 4 h urinary excretion of epinephrine (E) and norepinephrine (NE) measured for 48 h. After 20 days of VLCD the weight loss was higher in men than women (P < 0.01), E excretion increased in men more than in women (P < 0.01), and was correlated with weight decrement (r = 0.78; P < 0.01). NE excretion decreased in a similar way in both sexes. The present findings demonstrate sexual dimorphism in catecholamine excretion during VLCD and provide further evidence of the relative autonomy of adrenomedullary secretion from sympathetic nervous system activity.
Adolescent↗
[Urological and sexual evaluation of treatment of benign prostatic disease using Pygeum africanum at high doses].
This clinical study has been designed to evaluate the efficacy of an extract of Pygeum Africanum (Tadenan) (Roussel-Pharma) in patients suffering from prostatic hypertrophy or chronic prostatitis. The drug has been administrated to 18 patients, for 60 days, as double of standard dosage (200 mg/die per os, instead of 100 mg/die). Because of the high frequency of association of sexual disorders with those two pathologies, we have extended the study also to sexual disorders selecting patients suffering from prostatic hypertrophy or chronic prostatitis and, simultaneously, from sexual disturbances. No side effects have been observed during the treatment. The urinary disturbances have been evaluated by anamnesis and prostatic transrectal echography; sexual disorders have been evaluated by anamnesis and nocturnal penile tumescence and rigidity (NPTR) monitoring. Furthermore, dosage of serum levels of the hormones LH, FSH, Prolactin, 17 beta-Estradiol and Testosterone has been performed before and after therapy. Pygeum Africanum extract administration improved all the urinary parameters we investigated; prostatic echography relieved reduction of peri-urethral edema. Also an improvement of sexual behaviour has been obtained; but we have not found significant differences between serum hormonal levels before and after therapy, as well as for NPTR.
Aged↗
Effects of androgen treatment in impotent men with normal and low levels of free testosterone.
The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimum serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens.
Adult↗
Sexual behavior of men with isolated hypogonadotropic hypogonadism or prepubertal anterior panhypopituitarism.
Sexual behavior of men with secondary hypogonadism was studied. Seven of the thirteen subjects presented with hypogonadism secondary to isolated gonadotropin (Gn) deficit, whereas the other six had idiopathic prepubertal anterior panhypopituitarism. Testosterone (T) levels were low and did not differ between the two groups. All subjects were evaluated both during replacement therapy (Gn in the first group; Gn plus cortisone and thyroxine in the second group) and 2 months after withdrawal of Gn therapy. During and after withdrawal of Gn administration, men with isolated deficit of Gn retained sexual activity and nocturnal penile tumescence, although they were partially compromised compared with a control group; on the other hand, panhypopituitarics reported compromised sexual function during Gn treatment and no sexual function when Gn therapy was not given. We conclude that different lesions of the hypothalamus-pituitary axis were accompanied by varying degrees of sexual impairment in the two groups of men presenting both secondary hypogonadism and very low T levels.
Adult↗
The effects of testosterone administration and visual erotic stimuli on nocturnal penile tumescence in normal men.
Nocturnal penile tumescence (NPT), as circumference change and rigidity, and REM sleep were measured in eight normal eugonadal men in two controlled experiments. In the first, exposure to erotic film prior to sleep had no effect on frequency of REM or on NPT. In the second placebo controlled experiment 150 mg im testosterone enanthate administration was associated with enhanced rigidity of NPT but with no effect on frequency or circumference change of NPT and no effect on frequency of REM.
Adult↗
The endocrine effects of visual erotic stimuli in normal men.
Endocrine responses to erotic stimulation in the laboratory were assessed in eight normal subjects. Each subject was tested on two occasions. On one occasion only neutral stimuli were involved. After 15 min baseline, 30 min of films were shown. For the erotic condition on the other occasion, two 10-min erotic films were interspersed with 10 min of neutral film. Fifteen-minute blood samples were taken from the start of each test and continued for 5 hr after the films. Plasma was assayed for testosterone, LH, prolactin, cortisol, ACTH and beta-endorphin. Urine was collected for 4 hr before and 4 hr after the films; this was assayed for adrenaline, noradrenaline and dopamine. Sexual arousal occurred in response to the erotic films in all subjects, as shown by erectile and subjective responses. There were no significant changes in hormone or catecholamine levels following either the erotic or the neutral stimuli, except for a rise in cortisol during the neutral but not the erotic film. These results indicate that in the laboratory, substantial sexual response can occur without accompanying endocrine or biochemical changes.
Adrenocorticotropic Hormone↗
Adrenomedullary hyperactivity in type I diabetic patients before and during continuous subcutaneous insulin treatment.
Urinary norepinephrine (NE) and epinephrine (E) excretion was measured at 4-h intervals for 2 consecutive days in nine type I diabetic patients with no signs of autonomic neuropathy before and after 3 weeks of glycemic control with continuous insulin infusion (CSII). Twenty-four-hour urinary E excretion was significantly higher in the diabetic patients than in normal subjects both before and after the period of CSII treatment [mean, 198.9 +/- 20.6 +/- SE and 127.8 +/- 24.4 vs, 46.6 +/- 9.8 nmol/day; P less than 0.05 for both]. The values in each of the 4-h periods before and in two of three of the periods after the 3-week period of CSII were significantly higher than those in normal subjects. Total urinary NE excretion was similar to that in the normal subjects at both times. The 24-h urinary NE/E ratio was significantly lower in diabetic patients even after they had achieved good metabolic control, compared with that in normal subjects (1.4 +/- 0.2 vs, 11.6 +/- 3.7; P less than 0.03). These data demonstrate hyperactivity of the adrenal medulla in type I diabetic patients, which is only partially reversed by a short period of glycemic control.
Adrenal Medulla↗
Changes in the bioactivity to immunoreactivity ratio of circulating luteinizing hormone in impotent men treated with testosterone undecanoate.
Testosterone undecanoate was administered orally (80 mg twice daily) for 30 days to 10 impotent men with mild Leydig cell failure, age 28 to 42 years. Placebo was administered for 30 days both before and at the end of testosterone undecanoate therapy. Serum levels of bioactive LH, immunoreactive LH and testosterone were determined in basal conditions (day zero), 30 days after the first placebo administration, at the 15th and 30th day of testosterone undecanoate therapy, and at the end of the second treatment with placebo (90th day). Bioactive LH was measured by a sensitive and specific in vitro bioassay based on testosterone production by mechanically dispersed mouse Leydig cell preparations. Immunoreactive LH and testosterone were determined by a double-antibody RIA technique. The results were compared with those obtained in 30 untreated normal young men. In the basal state, serum concentrations of immunoreactive LH were significantly higher in the patients (P less than 0.02) than in control subjects, whereas testosterone levels were significantly lower (P less than 0.001) in the impotent men. In contrast, bioactive LH levels and the bioactive LH to immunoreactive LH ratios were similar in the two groups. In the patients, at the 15th day of treatment with testosterone undecanoate, serum levels of testosterone and bioactive LH were significantly higher (P less than 0.01) than basal values, whereas immunoreactive LH concentrations showed no significant changes. Consequently, the bioactive LH to immunoreactive LH ratios rose significantly (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Effects of cyproterone acetate, LHRH agonist and ovarian surgery in McCune-Albright syndrome with precocious puberty and galactorrhea.
We have studied the endocrinological pattern in a girl with McCune-Albright syndrome. The young patient showed: normal prepubertal serum levels of gonadotropins, fluctuating estrogen concentrations, which sometimes were similar to the levels in adult women of fertile age, hyperprolactinemia with galactorrhea, ovarian cysts. The effects of treatment with antiandrogen drug, cyproterone acetate, and of a LHRH agonist, buserelin (less than D-Ser[TBU(8)6-des-gly NH2.10 greater than LHRH ethylamide), were studied. Cyproterone acetate with or without buserelin did not fully suppress estradiol concentrations. On the other hand, surgical resection of these cysts resulted in both clinical and endocrinological remission. It is likely that in this case of McCune-Albright syndrome precocious puberty was a result of ovarian estrogen secretion, while pubertal activation of the hypothalamus-pituitary axis was absent. Hyperprolactinemia, which appeared after the beginning of the combined therapy with buserelin and cyproterone acetate, was probably due to the elevated estrogen levels.
Buserelin↗
Antiepileptic drugs and puberty.
This paper investigates pubertal development in 57 epileptic subjects, ranging in age from 6 to 15 years, under anti-epileptic therapy for at least 2 years. The results were compared with those from a control group of healthy volunteers. The onset of stage II puberty was significantly earlier in both male and female treated epileptics than in healthy control subjects: at this stage serum levels of 17-beta-estradiol (E2) were found to be significantly lower in treated epileptic females than in healthy control females and the serum levels of follicle-stimulating hormone (FSH) significantly lower in treated epileptic males than in control subjects. At stage III puberty, serum levels of FSH were significantly lower both in male and female treated epileptic than in healthy control subjects.
Adolescent↗
Further acquisitions on gonadal function in bromocriptine treated hyperprolactinemic male patients.
The diurnal variation of plasma total and free testosterone (tT and fT) and the gonadotropinemic response to LH-RH were evaluated in a group of hyperprolactinemic impotent males with pituitary microprolactinoma before and during therapy with bromocriptine, a well known dopamine agonist drug. Before treatment, basal levels not only of tT but also of fT were decreased and the diurnal variation of both tT and fT was absent. Moreover, the LH-RH test showed a delay in the LH response peak, together with normal basal levels of LH. Bromocriptine therapy caused normalization of both the secretion response of LH to LH-RH and of the secretion pattern of tT and of fT (basal levels and diurnal variation) besides a significant decrease in PRL levels and an improvement in sexual function. The possible effects of high plasma levels of PRL at various levels of the hypothalamus-pituitary-testicular axis are discussed.
Adult↗
The reproductive system in elderly men.
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Aged↗
Effects of acute stimulation with gonadotropin releasing hormone (GnRH) on biologically active serum luteinizing hormone (LH) in elderly men.
This study was designed to characterize the response pattern of biologically active LH (BIO-LH) after Gonadotropin Releasing Hormone (GnRH) acute administration in healthy elderly men, in comparison with normal young adult men. Serum levels of BIO-LH under basal conditions and in response to the iv injection of 0.1 mg synthetic GnRH were measured in 6 healthy elderly men (mean age 74.2 yr), as well as in 9 normal young men (mean age 27.4 yr). A sensitive in vitro bioassay, based upon testosterone production by mechanically dispersed mouse Leydig cells, was employed to assess LH biological activity. Levels of immunoreactive LH (RIA-LH) and basal testosterone (T) concentrations were determined by a double antibody radioimmunoassay technique. Mean basal levels of BIO-LH and RIA-LH were significantly increased in elderly men, compared to levels in young men, whereas the mean basal ratio of LH in vitro bioactivity to LH immunoreactivity (LH B/I ratio) and mean basal T concentrations were significantly lower in the elderly group. After GnRH administration, the B/I ratio of serum LH remained unchanged both in elderly and in young men. The mean relative maximum response for BIO-LH (BIO-LH delta %) was significantly lower in elderly men than in the younger male subjects, whereas mean BIO-LH response areas (BIO-LH delta areas) were not significantly different in the two groups. The mean peak response for both BIO-LH and RIA-LH was observed at 45 min in the elderly group and at 30 min in the younger subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Sexual behavior of male rats: influence of short- and long-term adrenalectomy.
Adult male rats (3 months old) were tested for their copulatory behavior: those satisfying the criterion of sexual vigor in the last three out of five weekly tests were randomly divided into two groups and adrenalectomized or sham operated, and their copulatory activity was retested 35 and 420 days after surgery. Short-term adrenalectomy did not modify any of the parameters of sexual behavior. On the other hand, a higher percentage of adrenalectomized than of sham-operated rats still had successful sexual performance when 18 months old (420 days after surgery); moreover, blood levels of testosterone were higher in adrenalectomized than in sham-operated old rats. The possibility that adrenal steroids may play a role in the age-linked decline in male sexual activity in mammals is discussed.
Adrenal Glands↗