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Biomedical subjects

B S Setty

Publications and source records attributed to B S Setty.

At least 37 records · Page 2Linked to original sources
PubMed1979

Regulation of epididymal function and sperm maturation--endocrine approach to fertility control in male.

The structural and functional integrity of the epididymis, the acquisition of fertilizing ability by spermatozoa and their viability within the epididymis are androgen dependent phenomena. Although the precise mechanism by which sperm maturation and viability in the epididymis are brought about by androgen are not clearly understood, it is generally held that specific epididymal secretions produced under the influence of androgen affect these events. Though the spermatozoa appear to remain viable in a low androgen environment, sperm maturation requires a relatively high androgen environment. Against this background the potentiality of antiandrogens as extragonadal antifertility agents has been discussed. Studies with steroidal and nonsteroidal antiandrogens have revealed that in adult animals the secretory activity of the epididymis, as evidenced by the level of glycerylphosphorylcholine, either remains unaffected or is stimulated under their influence. These studies have further indicated that the extragonadal antifertility action of antiandrogens will depend upon their ability to (1) lower the testicular androgen synthesis and/or androgen binding protein, which possibly serves as a carrier of androgen from the testis to epididymis; (2) to lower local androgen synthesis as a result of reduced levels of circulating androgen, and (3) to inhibit 5 alpha-reduction of testosterone to dihydrotestosterone and/or to inhibit androgen binding to receptors. Success in the rational development of new antifertility agents for male which will act by controlling epididymal function will depend upon a clear understanding of the factors that regulate epididymal secretion and the role of epididymal secretions in sperm maturation and survival.

Androgen Antagonists↗
PubMed1977

Androgenic control of epididymal function in rhesus monkey and rabbit.

The effects of castration and testosterone replacement therapy on the histology and biochemical composition (RNA, DNA, total protein, alkaline phosphatase, acid phosphatase, hyaluronidase, sialic acid, glycogen, phospholipids, and glycerylphosphorylcholine [GPC]) of the epididymis of the rabbit and rhesus monkey were investigated. Castration produced marked ponderal, histologic, and biochemical changes in the epididymis. In the androgen-deficient state the tubular diameter and epithelial cell height were reduced and there was an increase in interbular stroma. The levels of RNA, DNA, phospholipids, and GPC were also reduced in castrated animals. Testosterone treatment restored the histologic features and the levels of various biochemical constituents to a great extent but not to the intact control level. The importance of endocrine and exocrine factors of the testis in relation to epididymal function is discussed.

Alkaline Phosphatase↗
PubMed1977

Functional maturation of the epididymis in the rat.

Weight, histological and biochemical changes in the rat epididymis were investigated during prepubertal, pubertal and postpubertal periods. The phase of most rapid growth of the epididymis commenced at 21 days and extended to 60 days of age; this period corresponded closely to the onset of androgen production at 3 weeks and stabilization of the leydig cell number at 60 days. Histological differentiation in the caput epididymis started before sperm entry and was complete in the cauda only several days after the spermatozoa had appeared. The presence of appreciable quantities of glycerophosphorylcholine (GPC) and sialic acid in the epididymis of 21-day-old rats suggested inherent secretory ability of the epididymal epithelium. The concentrations of GPC, sialic acid, phospholipids and glycogen in the epididymis gradually increased with age, but each came under the influence of androgen at a different age. There was no evidence to suggest that the presence of spermatozoa has a stimulatory effect on the epididymis. Maximal secretory activity of the epididymis became established only by 90 days of age.

Animals↗
PubMed1977

Functional maturation of the epididymis in rabbit and rhesus monkey.

The changes in the weight, histology and biochemical composition of the epididymis (caput, corpus and cauda segments) in prepuberal rabbit and rhesus monkey in response to testosterone treatment were investigated. The increase in the weight of the organ was accompanied by increased levels of RNA and DNA. Androgen therapy caused an increase in the concentration of sialic acid, phospholipids and glycerylphosphorylcholine and activities of alkaline phosphatase, acid phosphatase and hyaluronidase. The cauda region of the epididymis exhibited relatively higher levels of sialic acid and glycerylphosphorylcholine. These findings are discussed in relation to the functional maturation of the organ and the role of androgen in this process.

Acid Phosphatase↗
PubMed1977

Influence of sex steroids on the secretory function of the epididymis in castrated rats.

Secretory response of the epididymis to exogenously administered testosterone, estrogen and progesterone was investigated using the levels of sialic acid and glycerylphosphorylcholine as indices. Testosterone was found to be most potent in stimulating the (GPC) secretory function of the organ. An enigmatic finding of the present study was that while estrogen showed the ability to stimulate both sialic acid and GPC levels, progesterone exerted its influence only on sialic acid. Studies on the accessory genital organs (weight of seminal vesicles and ventral prostate and fructose level of coagulating gland) also revealed a stimulatory effect of the steroids.

Animals↗
PubMed1976

Studies on the physiology and biochemistry of mammalian epididymis: effect of flutamide, a nonsteroidal antiandrogen, on the epididymis of the rat.

The effect of flutamide (Sch 13521; 4'-nitro-3'-trifluoromethylisobutyranilide), a nonsteroidal antiandrogen, on male rat genital organs was studied. Administered at a dose of 25 mg/kg body weight daily for 30 days, flutamide caused a significant increase in the weight of the testis but had no effect on spermatogenesis and Leydig cell morphology. The secretory activity of the epididymis, as evidenced by the level of glycerylphosphoryl-choline and sialic acid, either remained unaffected or was stimulated. There was a significant decrease in seminal vesicle and ventral prostate weight and in the fructose content of the coagulating gland. The anti-androgen at the dose used did not affect the fertility of the rats. The significance of these findings is viewed in relation to the hypothesis of a differential threshold requirement of androgen for the epididymis and the accessory sex glands. The potentiality of antiandrogens as extragonadal antifertility agents in the male is discussed.

Anilides↗
PubMed1976

Antifertility agents. 12. Structure-activity relationship of 3,4-diphenylchromenes and -chromans.

Synthesis and antiimplantation activity of variously substituted 2,2-dialkyl-3,4-diphenylchromenes and 3,4-cis- and trans-chromans derived from them are described. Pregnancy-inhibiting activity in rats was exhibited by a number of these compounds, which was particularly marked in the case of 3,4-trans-3-phenyl-4-p-(beta-pyrrolidinoethoxy)-phenyl-7-methoxychroman (32), the corresponding 2,2-dimethyl analog 34, and 3-phenyl-4-p-(beta-pyrrolidinoethoxy)phenyl-7-methoxychromene (26). The structure-activity relationship of these compounds is discussed.

Animals↗
PubMed1976

Epididymal response to exogenous testosterone in rats sterilized neonatally by estrogen.

Male rats treated with estradiol dipropionate (250 mug) by subcutaneous injection on Day 5 of postnatal life failed to show maturation changes in the testis and epididymis at puberty. Histological examination at 60 days revealed inhibition of spermatogenesis at primary spermatocyte stage and atrophic Leydig cells. Epididymis presented infantile features and there was a marked reduction in the secretory activity as revealed by lowered concentration of sialic acid and glycerylphosphorylcholine. Testosterone therapy (1 mg/day) for a period 45 days prior to autopsy at 60 days failed to induce completion of spermatogenesis but restored the structural and functional integrity of the epididymis.

Animals↗