Role of 1α,25(OH)2 vitamin D3 on α-[1-14C]MeAIB accumulation in immature rat testis

Abstract We have investigated the role of Ca2+ in the control of FSH-induced estradiol secretion by Sertoli cells isolated from 8-10 days old rats. Exogenous Ca2+ (4-8 mmol/1) inhibited FSH-stimulated E2 secretion such that, with 8 mmol/l Ca2+ and FSH (8 IU/l) E2 secretion decreased from 2091±322 to 1480±84 pmol/l (p<0.002), whilst chelation of Ca2+ in the culture medium with EGTA (3 mmol/l) increased E2 secretion from 360±45 to 1242±133 pmol/l) in the absence of FSH. Further, EGTA (3 mmol/l) markedly potentiated FSH (8 IU/l), forskolin (1 μmol/l) and dibutyryl cAMP (1 mmol/l)-stimulated E2 secretion. Addition of the Ca2+ ionophores, ionomycin (2-5 μmol/l) and A23187 (2 μmol/l), inhibited FSH (8 IU/l)-stimulated E2 secretion by >80%. The effect of ionomycin was totally reversible, whereas that of A23187 was irreversible. Ionomycin (5 μmol/l) had no effect on EGTA-induced E2 secretion in the absence of FSH, but reduced EGTA-provoked E2 secretion by 59% in the presence of FSH (8 IU/l). Similarly, forskolin- and dibutyryl cAMP-provoked E2 production was inhibited 46-50% by ionomycin (5 μmol/l). We conclude that FSH-induced E2 secretion from immature rat Sertoli cells is modulated by intra- and extracellular Ca2+.

Download Full-text

SUBLINGUAL VITAMIN D3 DRUG THERAPY IN VITAMIN D DEFICIENCY PATIENTS AT PRAVARA RURAL HOSPITAL

International Journal of Clinical and Biomedical Research ◽

10.31878/ijcbr.2019.54.05 ◽

2019 ◽

pp. 18-20

Author(s):

Sanjeeva Kumar Goud T ◽

Rahul Kunkulol

Keyword(s):

Vitamin D ◽

Vitamin D Deficiency ◽

Vitamin D3 ◽

Serum Vitamin ◽

Cross Sectional ◽

Serum Vitamin D ◽

Significant Difference ◽

Before And After

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route

Download Full-text

POSSIBLE ROLE OF 5α-ANDROSTANE-3α,17β-DIOL IN THE CONTROL OF FOLLICLE-STIMULATING HORMONE SECRETION IN THE IMMATURE FEMALE RAT

Journal of Endocrinology ◽

10.1677/joe.0.0920037 ◽

1982 ◽

Vol 92 (1) ◽

pp. 37-42 ◽

Cited By ~ 10

Author(s):

H. M. A. MEIJS-ROELOFS ◽

P. KRAMER ◽

L. GRIBLING-HEGGE

Keyword(s):

Inhibitory Action ◽

Combined Treatment ◽

Hormone Secretion ◽

Inhibitory Effect ◽

Ovariectomized Rats ◽

Female Rat ◽

Immature Rat ◽

Rat Strain ◽

Intact Rats

A possible role of 5α-androstane-3α,17β-diol (3α-androstanediol) in the control of FSH secretion was studied at various ages in ovariectomized rats. In the rat strain used, vaginal opening, coincident with first ovulation, generally occurs between 37 and 42 days of age. If 3α-androstanediol alone was given as an ovarian substitute, an inhibitory effect on FSH release was evident with all three doses tested (50, 100, 300 μg/100 g body wt) between 13 and 30 days of age; at 33–35 days of age only the 300 μg dose caused some inhibition of FSH release. Results were more complex if 3α-androstanediol was given in combined treatment with oestradiol and progesterone. Given with progesterone, 3α-androstanediol showed a synergistic inhibitory action on FSH release between 20 and 30 days of age. However, when 3α-androstanediol was combined with oestradiol a clear decrease in effect, as compared to the effect of oestradiol alone, was found between 20 and 30 days of age. Also the effect of combined oestradiol and progesterone treatment was greater than the effect of combined treatment with oestradiol, progesterone and 3α-androstanediol. At all ages after day 20 none of the steroid combinations tested was capable of maintaining FSH levels in ovariectomized rats similar to those in intact rats. It is concluded that 3α-androstanediol might play a role in the control of FSH secretion in the immature rat, but after day 20 the potentially inhibitory action of 3α-androstanediol on FSH secretion is limited in the presence of oestradiol.

Download Full-text

Late spermatocytes from immature rat testis isolation, electron microscopy, lectin agglutinability and capacity for glycoprotein and sulfogalactoglycerolipid biosynthesis

Biochimica et Biophysica Acta (BBA) - General Subjects ◽

10.1016/0304-4165(78)90267-2 ◽

1978 ◽

Vol 541 (1) ◽

pp. 59-75 ◽

Cited By ~ 15

Author(s):

Pamela J. Letts ◽

Richard C. Hunt ◽

Margaret A. Shirley ◽

Les Pinteric ◽

Harry Schachter

Keyword(s):

Electron Microscopy ◽

Immature Rat ◽

Rat Testis

Download Full-text

A Clinical Study to Evaluate the Role of Vitamin D3 in Allergic Rhinitis

Indian Journal of Otolaryngology and Head & Neck Surgery ◽

10.1007/s12070-021-03004-x ◽

2022 ◽

Author(s):

Gopika Kalsotra ◽

Aditiya Saraf ◽

Apurva Raina ◽

Parmod Kalsotra ◽

Rupali Sharma ◽

...

Keyword(s):

Allergic Rhinitis ◽

Clinical Study ◽

Vitamin D3

Download Full-text

Ligand modulates the conversion of DNA-bound vitamin D3 receptor (VDR) homodimers into VDR-retinoid X receptor heterodimers

Molecular and Cellular Biology ◽

10.1128/mcb.14.5.3329-3338.1994 ◽

1994 ◽

Vol 14 (5) ◽

pp. 3329-3338

Author(s):

B Cheskis ◽

L P Freedman

Keyword(s):

Ligand Binding ◽

Vitamin D3 ◽

Hormone Receptors ◽

Steroid Receptors ◽

Dependent Manner ◽

D3 Receptor ◽

Vitamin D3 Receptor ◽

Binding Domains

Protein dimerization facilitates cooperative, high-affinity interactions with DNA. Nuclear hormone receptors, for example, bind either as homodimers or as heterodimers with retinoid X receptors (RXR) to half-site repeats that are stabilized by protein-protein interactions mediated by residues within both the DNA- and ligand-binding domains. In vivo, ligand binding among the subfamily of steroid receptors unmasks the nuclear localization and DNA-binding domains from a complex with auxiliary factors such as the heat shock proteins. However, the role of ligand is less clear among nuclear receptors, since they are constitutively localized to the nucleus and are presumably associated with DNA in the absence of ligand. In this study, we have begun to explore the role of the ligand in vitamin D3 receptor (VDR) function by examining its effect on receptor homodimer and heterodimer formation. Our results demonstrate that VDR is a monomer in solution; VDR binding to a specific DNA element leads to the formation of a homodimeric complex through a monomeric intermediate. We find that 1,25-dihydroxyvitamin D3, the ligand for VDR, decreases the amount of the DNA-bound VDR homodimer complex. It does so by significantly decreasing the rate of conversion of DNA-bound monomer to homodimer and at the same time enhancing the dissociation of the dimeric complex. This effectively stabilizes the bound monomeric species, which in turn serves to favor the formation of a VDR-RXR heterodimer. The ligand for RXR, 9-cis retinoic acid, has the opposite effect of destabilizing the heterodimeric-DNA complex. These results may explain how a nuclear receptor can bind DNA constitutively but still act to regulate transcription in a fully hormone-dependent manner.

Download Full-text

Intestinal absorption of calcium: role of dietary phosphate and vitamin D

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1981.241.1.g49 ◽

1981 ◽

Vol 241 (1) ◽

pp. G49-G53

Author(s):

N. Brautbar ◽

B. S. Levine ◽

M. W. Walling ◽

J. W. Coburn

Keyword(s):

Vitamin D ◽

Intestinal Absorption ◽

Vitamin D3 ◽

Control Groups ◽

Dihydroxyvitamin D3 ◽

Dietary Phosphorus ◽

P Concentration ◽

Dietary Phosphate ◽

Intestinal Ca Absorption

The intestinal absorption of calcium (Ca) has been shown to depend on vitamin D3, 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], and dietary phosphorus (P) concentration. This study was designed to evaluate the role of dietary P independent of vitamin D3 or 1,25(OH)2D3. Vitamin D-deficient rats were studied during dietary P restriction and were compared with control groups raised on a normal-phosphorus diet (NP). Balance studies were sued. Net intestinal Ca absorption was significantly lower with dietary P restriction compared with the NP group. This malabsorption of Ca was corrected by the administration of either D3 for 1,25(OH)2D3, despite hypophosphatemia. Everted gut sacs showed a marked reduction in the uptake of 45Ca in the duodenum, jejunum, and ileum during dietary P restriction. We concluded that dietary P concentration plays a major role in intestinal Ca absorption in the vitamin D-deficient rats. These findings suggest an effect of the low-phosphate diet on the vitamin D-dependent, Ca-transport mechanism.

Download Full-text