Testosterone plasma

GuiUette, Jr., L.J., Pickford, D.B., and Crain, D.A. et al. (1996). Reduction in penis size and plasma testosterone concentrations in juvenile alligators living in a contaminated environment. General and Comparative Endocrinology 101, 32-42. 

Fig. 7.11 Inhibitory effect of alpha-Male urine on plasma Testosterone [T. ng/ml]. Exposure to urinary fractions in isolated (subordinate) male Mouse lemurs (N = 10) vs. castrate/adrenalectomised Ss, p < 0.001 vs. control (from Perret, 1995).

D Angelo W., Macrides F. and Bartke A. (1974). Effects of exposure to vaginal odor and receptive females on plasma testosterone in the male hamster. Neuroendocrinol 15, 355-364. 

Purvis K. and Haynes N. (1978). Odours of female rat urine on plasma testosterone in male rats. J Reprod Fertil 53, 63-65. 

Rat (Sprague-Dawley) Gd 5-21 PNd 21-85 ad lib (W) 42 (reduced plasma testosterone and 17B-estradiol at birth) Ronis et al. 1998b, 1998c PbAc... 

Androgenic deficiency in male rats given a single oral dose of 15 pg 2,3,7,8-TCDD/kg BW was evident as early as 2 days posttreatment, with persistence up to 12 days. These deficiencies may account for male reproductive pathology and dysfunction in rats treated with overtly toxic doses of TCDD. Findings included depression in plasma testosterone concentrations, as well as decreased weight of seminal vesicles (by 68%), ventral prostate gland (by 48%), testes, and epididymis (Moore et al. 1985). 

Twigg, L.E., D.R. King, and A.J. Bradley. 1988a. The effect of sodium monofluoroacetate on plasma testosterone concentration in Tiliqua rugosa (Gray). Comp. Biochem. Physiol. 91C 343-347. 

Ketoconazole inhibits a variety of cytochrome P450 enzymes, including 11-hydroxylase and 17-hydroxylase. It is highly effective in lowering cortisol in Cushing s disease, and patients can be maintained successfully on therapy for months to years. The most common adverse effects are reversible elevation of hepatic transaminases and GI upset. It can cause gynecomastia and lower plasma testosterone values. 

Only 2% of total plasma testosterone is present in the active unbound state that penetrates the prostate cell, where it is converted to DHT by 5 a-reductase. DHT subsequently binds with a cytoplasmic receptor and is transported to the cell nucleus where transcription and translation of stored genetic material occur. 

Prenatal and postnatal exposures to fenvalerate reduced prostate and seminal vesicle weights and plasma testosterone levels in male rats [55], A chronic study showed no adverse effects on reproductive tissues at a high dose level of 1,000 ppm [142]. In vivo and in vitro studies with rats and mice suggested that fenvalerate may affect male and female reproduction, possibly due to calcium transport alteration [143-146], One paper reported that fenvalerate affected human sperm count and sperm motility of male workers who were exposed to fenvalerate in a pesticide factory [147]. 

Tarttelin, M.F., Hendriks, W.H. and Moughan, P.J. (1998) Relationship between plasma testosterone and urinary felinine in the growing kitten. Physiol. Behav. 65, 83-87. 

Kreuz, L. E., and Rose, R. M. 1972. Assessment of aggressive behavior and plasma testosterone in a young criminal population. Psychosomatic Medicine 34 321—332. 

As would be expected, khat overuse produces symptoms similar to those of other monoamine stimulants, such as cocaine or amphetamine, including signs of sympathetic overarousal. In the extreme this can involve a toxic psychosis. Disorders more frequently associated with chronic khat use in males are headaches, anorexia, insomnia, constipation, and respiratory illnesses (Kennedy et al. 1983). Females report higher incidences of acute gastritis, jaundice, bronchitis and hepatic diseases. Also, cathinone has toxic reproductive effects in humans and experimental animals (Islam et al. 1990). It decreases sperm count and motility, and increases the number of abnormal sperm cells. It also decreases plasma testosterone in rats. 

Plasma prolactin levels are reduced with acute treatment and remain suppressed after 28 days of chronic treatment (Murphy et al. 1998). With acute treatment, no effects are seen on plasma luteinizing hormone or testosterone levels. However, chronic dietary 5% ginseng increases testosterone levels in male rats (Fahim et al. 1982). Chronic ginsenosides do not alter posterior pituitary hormones oxytocin and vasopressin (Zierer 1991). Similarly, human males administered ginseng extract showed an increase in plasma testosterone, dihydrotestosterone, follicle-stimulating hormone, and luteinizing hormone, but a decrease in prolactin (Salvati et al. 1996). 

In mice, strange females or their urine increase the levels of plasma testosterone in males (Macrides etal., 1975). Experienced male golden hamsters, on the other hand, do not depend on specific pheromonal odors for this testosterone surge induced by estrous females. Other cues, possibly learned odors from a female, perceived via the main olfactory system, appear to activate the neuroendocrine refiex that results in increased testosterone release (Johnston, 2001). 

Anal gland secretion of male short-tailed voles, M. agrestis, stimulates plasma testosterone, body weight, and anal gland size in other males. The biological significance of this effect is unclear (Khan and Stoddart, 1986). 

In a primate, Microcebusmurinus Tiosimi3L) male odor depresses the level of plasma testosterone in other males. The lipid fraction (ether extract) of male... 

Macrides, F., Bartke, A., and Dalterio, S. (1975). Strange females increase plasma testosterone levels in male mice. Science 189,1104-1106. 

Endocrine effects Statins interfere with cholesterol synthesis and lower circulating cholesterol levels and, as such, might theoretically blunt adrenal or gonadal steroid hormone production. Small declines in total testosterone with no commensurate elevation in LH have been noted with the use of fluvastatin. Pravastatin showed inconsistent results with regard to possible effects on basal steroid hormone levels atorvastatin, lovastatin, rosuvastatin, and simvastatin did not reduce basal plasma cortisol concentration or basal plasma testosterone concentration or impair adrenal reserve. Appropriately evaluate patients who display clinical evidence of endocrine dysfunction. Exercise caution when administering HMG-CoA reductase inhibitors with drugs that affect steroid levels or activity, such as ketoconazole, spironolactone, and cimetidine. 

Concentrations of plasma testosterone and other androgens vary throughout the day in both sexes whether such variation is simply random or fits a repeatable diurnal pattern is a matter of debate. Compared with the diurnal variation seen with cortisol, plasma testosterone concentrations are reasonably constant. Plasma androgen concentrations also vary greatly in women through the menstrual cycle, with peak levels seen in the luteal phase. 

The catabolism of plasma testosterone and other androgens occurs primarily in the liver (Fig. 63.3), where they are conjugated into water-soluble compounds that are excreted by the kidney as the urinary 17-ketosteroids. 

Hardman, ]. T., M. L. Beck and C. E. Owensby. Range forb lectins. Transfusion 1983 23(6) 519-522. Mendelson, ]. H., ]. Ellingboe, ]. C. Kuehnle and N. K. Mello. Effects of chronic marihuana use on integrated plasma testosterone and luteinizing hormone levels. J Pharmacol Exp Ther 1978 207 611-617. 

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