Sex difference in glucose-6-phosphate dehydrogenase activity in the submandibular gland of mice

Sex-dependent differences in the concentrations of the principal neurotransmitters, noradrenaline and acetylcholine, in the three major salivary glands of mice

The concentrations of principal neurotransmitters in the submandibular, parotid and sublingual glands were compared between two pairs of age-matched male and female ddY mice, one pair consisting of 4-week-old and the other 8-week-old animals. Sex-dependent differences in both noradrenaline and acetylcholine concentrations were observed only in the submandibular gland, although each neurotransmitter showed distinct features. The acetylcholine concentration in the submandibular gland was higher in the female at both ages, whereas the noradrenaline concentration was higher in the female at the age of 4 weeks but became higher in the male by the age of 8 weeks. On the other hand, the total amounts of noradrenaline and acetylcholine per submandibular gland were already greater in the male at 4 weeks, and the male parotid and sublingual glands also had a greater noradrenaline content by 4 weeks and 8 weeks, respectively. Each type of gland had similar growth rates over the 4-week period, and the male submandibular and parotid glands were heavier than the female. In addition, each type of gland had its characteristic ratio of noradrenaline to acetylcholine concentration, which did not differ between the sexes and remained in similar basic patterns during the period examined, except for the submandibular gland of 8-week-old male mice, which developed greater amounts of the sympathetic neurotransmitter noradrenaline.

Ultrastructure of the main excretory duct epithelium of the female mouse submandibular gland with special reference to sexual dimorphism

The fine structure of the main excretory duct epithelium (MEDE) of female mouse submandibular gland was investigated by scanning and transmission electron microscopy and the results compared with the previously established structure of male mouse MEDE. A comparative analysis of the subepithelial capillaries of both sexes was also performed. In this pseudostratified epithelium, principal cell-types were observed: types-I, -II, -III and basal cells. This differed significantly from male MEDE, where type-II and -III are absent and type-I cells are the most numerous. The latter cell-type had abundant mitochondria, a few lipid-containing granules, lysosomes in the infra-nuclear cytoplasm and well-developed basal infoldings. These cells were also characterized by abundant glycogen granules throughout the cytoplasm, many profiles of strands of smooth endoplasmic reticulum in the apical region, and lysosomes in the infranuclear region. Type-II cells were the second most numerous. Their most characteristic features were the presence of tubular vesicles which appeared to be invaginated from the plasma membrane, RER, SER, free ribosomes, a few peroxisomes with nucleoids, and primary lysosomes in extremely light cytoplasm. They had many mitochondria throughout the cytoplasm, except in the apical region, a few lipid-containing granules and no basal infoldings. Type-III cells were very few and were characterized by well developed basal infoldings, abundant free ribosomes, RER, SER, vesicles containing moderately dense material, and many lipid-containing granules. They also had many mitochondria throughout the cytoplasm, except apically. Basal cells had a large nucleus and the cytoplasm had few organelles.(ABSTRACT TRUNCATED AT 250 WORDS)

Histochemical study of the human bulbourethral (Cowper's) glands

Human bulbourethral glands were reacted histochemically and immunohistochemically to identify glycoproteins, some androgen metabolic enzymes, and VIP-like immunoreactivity. Neutral/acid mucosubstances were detected in the cytoplasm of the tubuloalveolar and ductal cells. 3 beta-, 17 beta-, and 3 alpha-hydroxysteroid dehydrogenase, G6PD, and 6PGD reactivity were intense in all the glandular epithelium. Small amounts of VIP-positive fibres were observed around the secretory elements.

Histochemistry of human urethral glands

Human urethral glands were reacted histochemically and immunohistochemically to identify glycoproteins, some androgen metabolic enzymes, and VIP-like immunoreactivity. Neutral/acid mucosubstances were detected mainly in the apical cytoplasm of the principal cells. 3 beta-, 17 beta-, and 3 alpha-hydroxysteroid dehydrogenase, G6PD, and 6PGD reactivity were intense in all the glandular epithelium. Small amounts of VIP-positive fibers were noted around the secretory elements.

Progesterone metabolism by major salivary glands of rat--II. Parotid gland

The metabolism of [4-14C]progesterone in the parotid salivary glands of nonpregnant female, pregnant female and male rats were investigated in vitro. The metabolic activity of the male rats was significantly lower than in either of the female groups. The pregnant group was metabolically more active than the nonpregnant female group, but his differences was not statistically significant. I homogenates and soluble fractions the main metabolite was 20-alpha-hydroxy- 4-pregnen-3-one in female rats. In male rats the main metabolites were 20-alpha-hydroxy-4- pregnen-3-one and 3-alpha-hydroxy-5-alpha-pregnan-20-one in homogenates and 20-alpha-hydroxy-4- pregnen-3-one in soluble fractions. In the microsomal fractions of both sexes polar compounds predominated. The results indicated the presence of at least the following progesterone metabolizing enzymes in art parotid salivary glands; 3-alpha-, 3-beta-, 20-alpha- and 20-beta-hydroxysteroid dehydrogenase, 5-alpha-and 5-beta-steroid hydrogenase and 17-alpha-steroid hydroxylase activities. Ind the homogenates and soluble fractions of female rats 20-alpha-hydroxysteroid dehydrogenase activity was significantly higher than in males.

Progesterone metabolism by major salivary glands of rat--I. Submandibular and sublingual glands

The metabolism of progesterone by the submandibular and sublingual salivary glands of female (nonpregnant and pregnant) and male rats was studied. The metabolism was in both sexes significantly greater in submandibular than in sublingual glands. Sex differences were not seen in sublingual glands but less metabolism was found in homogenates and microsomal fractions of female (nonpregnant and pregnant) submandibular glands compared to that of males. The metabolism did not differ between pregnant and nonpregnant female rats. The metabolites were mainly 5 alpha-pregnane-compounds. On the basis of the metabolites identified it can be concluded that rat submandibular and sublingual glands contain at least 3 alpha-, 3 beta-, 20 alpha- and 20 beta-hydroxysteroid dehydrogenase, 5 alpha- and 5 beta-steroid hydrogenase and 17 alpha-steroid hydroxylase activity. 5 alpha-steroid hydrogenase activity was significantly higher in all preparations of male submandibular glands than in females. In sublingual glands some enzyme activities showed pregnancy-related decreased.

Sex and strain differences of mouse variant salivary proteins

Proteins of the mouse saliva are resolved into about 20 discrete bands by polyacrylamide gel electrophoresis. Sexual dimorphism and monomorphism were found in a subset (Msp-1) of these salivary proteins from different inbred strains. This sexual dimorphism involves a fast moving band (F-type) and a slow moving one (S-type). Mature males of seven strains (A/J, AKR, CBA/J, C3H/HeN, A/Sn, B10.A, and B10.BR) exhibit the S phenotype while mature females of these strains were typed as F. Sexually immature males and females of these strains were uniformly typed as F, but at puberty (5-6 weeks of age) the phenotype of the males switched to type S, while the phenotype of the females remained the same. This switch to type S at puberty did not take place in males of four strains (BALB/cAnn, B10.D2, C57BL/6, and C57BL/10); therefore, we conclude that these strains were sexually monomorphic with regard to Msp-1. The phenotype of mature males of C3H/HeN reverted to type F following castration, whereas castrated males and mature females switched to type S in response to testosterone administration. The testosterone treatment had no effect on the type S phenotype of males and females of the sexually monomorphic BALB/cAnn strain. The male-specific type S phenotype of Msp-1 was seen only in mice with H-2 haplotype a or k; thus an association with H-2 haplotype was suggested. All F1 males of reciprocal crosses involving the sexually dimorphic and monomorphic strains (e.g., C3H/HeN X BALB/cAnn) demonstrated the type S phenotype at puberty.

Developmental and sex-dependent regulation of storage protein synthesis in the silkworm, Bombyx mori

The mechanism of sex-dependent expression of a major plasma protein, referred to as storage protein 1 (SP-1) was studied during development of the silkworm, Bombyx mori. SP-1 occurred in the hemolymph of the female as well as in the male larvae until the end of the fourth larval instar. In the last instar larvae, the amount of SP-1 in the hemolymph greatly increased in females, but markedly declined in males. The level of fat body mRNA for SP-1 reflected the developmental and sex-dependent changes in the hemolymph concentration of SP-1. The developmental patterns of hemolymph proteins in the third and the fourth instar larvae of sex-mosaic individuals were quite analogous to those observed in normal larvae at the same developmental stages. The hemolymph concentration of SP-1 at the last larval instar of the sex mosaics varied among individuals irrespective of the gonad compositions. In vitro culture of the fat body cells dissected from several locations of a sex-mosaic larva provided evidence that each fat body cell in a common hemolymph milieu synthesizes a high (female type) or a low (male type) level of SP-1 depending on the sex chromosome composition. The amount of vitellogenin in the hemolymph of the sex-mosaic pupae was in proportion to that of SP-1 at the last larval instar. From these results, it is suggested that the sex-dependent expression of SP-1 and vitellogenin in B. mori is genetically determined and developmentally regulated without participation of the reproductive organs or any sex-specific humoral factors.

Steroid metabolism by normal and neoplastic parotid tissue

The metabolism of steroid hormones in normal and neoplastic tissue has been studied in the human parotid gland. In vitro incubation of homogenate preparations with either testosterone, oestradiol or DHT resulted in the formation of the corresponding 17-keto metabolite as the major product. Little or no metabolism could be seen when androstenedione, oestrone or 5 alpha-androstan-3,17-dione were used as substrates, demonstrating that the 17 beta-hydroxysteroid dehydrogenase (17 beta-HSDH) in this tissue favours an oxidative reaction pathway, 17 beta-HSDH activity in normal and tumour tissue was compared using both testosterone and oestradiol as substrates. The activity varied between individuals but was, in all cases, significantly elevated in tumour tissue when this was compared with normal. In conclusion, (1) the human parotid gland contains steroid metabolizing enzymes which favour an oxidative reaction pathway, and (2) the 17 beta-HSDH activity is significantly elevated in neoplastic tissue.

Histochemistry of the 3 beta-hydroxysteroid, 17 beta-hydroxysteroid and 3 alpha-hydroxysteroid dehydrogenases in human salivary glands

Human parotid and submandibular glands showed no 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) activity. The 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and the 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) appeared intensely reactive in the duct epithelia of the male and female glands and weakly reactive in the acinar cells of the female ones. The failure to demonstrate 3 alpha-HSD activity indicates that in-vivo androgen activation, if present at all, is not so marked as in target organs. The different distribution of the 3 beta-HSD and 17 beta-HSD in the two sexes can be related not only to the oxidation of androgens but also to the metabolism of the female hormones. Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) do not seem to be specifically influenced by the sex hormones as their pattern of distribution showed no sex differences.

Sexual dimorphism of SDS peptide patterns from the submaxillary glands of mice

In mice (Mus musculus) sexual dimorphism is evident in the structure and function of the submaxillary glands, convoluted tubules being much more prominent in males than in females. Several enzymes are more abundant in the male gland. We have examined the submaxillary glands of male and female mice for the amounts of arginine peptidase and have made electrophoretic scans of SDS peptides in extracts of male and female glands during postnatal development and after androgen treatment. Larger peptides are relatively more abundant in female extracts, and smaller peptides are more abundant in the male extracts. The peptide patterns reflect the amount of arginine peptidase present in the extracts. No arginine peptidase could be detected in submaxillary salivary glands of mice from birth until 3 weeks of age. Then enzyme activity gradually increased, apparently induced by androgen hormones. The amounts of SDS peptides of high molecular weight steadily decreased with increasing age of the mouse and with increasing titers of arginine peptidase. Castration of the male led to the appearance of female SDS patterns; male patterns reappeared after treatment with testosterone. Females could be induced to form male patterns of SDS peptides by treatment with androgen hormones.

Histochemistry of some steroid-dehydrogenases in epithelia of human seminal vesicle, deferential ampulla, and prostate gland

The cytochemical localization of 17 beta-SDH, 3 beta-SDH, and 3 alpha-SDH was made in human seminal vesicle, deferential ampulla and prostate. The enzymes showed a remarkable activity in the epithelial cells of all glands. The epithelia of prostate, seminal vesicle, and deferential ampulla were able to metabolize androgens through the reductive pathway, characteristic of target tissues.

Genetic and endocrine control of renin activity in the submaxillary gland of the mouse

Basal activity of submaxillary gland (SMG) renin is high in female mice that carry the Rnrs allele and is induced to higher levels by treatment with dihydrotestosterone (DHT). To determine whether the difference in basal activity between high (Rnrs/Rnrs) and low (Rnrb/Rnrb) strains is due to enhanced sensitivity of Rnrs/Rnrs strains to endogenous androgen, we first studied the effect of several types of endocrine ablation on SMG renin in young female mice, and second, we removed normal androgen receptor protein by introducing the X-linked Tfm gene. Adrenalectomy with or without castration had no effect on basal SMG renin; hypophysectomy decreased basal renin activity 400-fold but did not abolish responsiveness to DHT. Loss of androgen receptor did not affect basal renin activity but did prevent enhancement by DHT. Basal and induced renin activities in L.AKR(Alll)/Cy, a congenic strain homozygous for Rnrs introduced from AKR/J into the background of C57L/J, an Rnrb/Rnrb type strain, are intermediate between levels observed in the original strains. We conclude that (1) the basal level of SMG renin is regulated directly or indirectly by some pituitary hormone(s) but not by androgen, (2) androgen induction of renin activity requires a normal androgen receptor, and (3) major gene(s) that regulate basal as well as induced SMG renin are in a circumscribed region of chromosome 1.

Effect of sex hormones on glucose-6-phosphate dehydrogenase in rat levator ani muscle

We studied the influence of sex hormones using the hormone-sensitive levator ani muscle as a model tissue and glucose-6-phosphate dehydrogenase as an indicator of hormone action. Injection of testosterone or estradiol cause a 50% increase in the specific activity of glucose-6-phosphate dehydrogenase. The effect was dose-dependent, and was maximal at a dose of 2.5mg/100g body weight. Estradiol increased glucose-6-phosphate dehydrogenase as early as 8 h after injection, while testosterone required 12 h. Injection of estradiol on 2 successive days increased enzyme activity by 80%. The effect of estradiol was abolished by actinomycin D, suggesting enzyme induction. The results indicate a direct effect of estrogen on striated muscle.

Histochemical study on the localization of glucose-6-phosphate dehydrogenase induced by androgen or thyroxine in the convoluted tubules of mouse submandibular gland

The effects of 5 alpha-dihydrotestosterone (DHT) and thyroxine (T4) on glucose-6-phosphate dehydrogenase (G-6-PDH) activity in mouse submandibular gland were investigated histochemically. A strong positive histochemical reaction for G-6-PDH was observed in the excretory ducts of untreated male and female mice, with a slight reaction in the basal portion of the convoluted tubules (striated ducts) of males. Administration of DHT to female mice increased G-6-PDH activity specifically in the convoluted tubules. T4 increased the enzyme activity in the tubules more than DHT. The induction of G-6-PDH activity by T4 in adrenalectomized mice suggests that T4 has a direct effect on the submandibular gland.

Synergistic effects of thyroxine and glucocorticoid in induction of trypsin-like esteroprotease in mouse submandibular gland

The actions of thyroxine, 5 alpha-dihydrotestosterone and hydrocortisone singly or in combination in enzyme regulation in the submandibular gland were studied in intact and adrenalectomized female mice. 1. Adrenalectomy decreased the activity of trypsin-like esteroprotease (EC 3.4.4.-), and administration of hydrocortisone to adrenalectomized mice restored the activity to normal. 2. Hydrocortisone and thyroxine had synergistic effects in induction of esteroprotease in adrenalectomized mice, but 5 alpha-dihydrotestosterone and hydrocortisone did not have synergistic effects in either intact or adrenalectomized mice. 3. The activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) was not influenced by change in the glucocorticoid level, but was increased by thyroxine and 5 alpha-dihydrotestosterone in both adrenalectomized mice and intact mice.4. Isoelectric focusing in polyacrylamide gel showed that there are three distinct activities of esteroprotease in this gland with isoelectric points of 5.6, 6.2 and 7.3. Both thyroxine and 5 alpha-dihydrotestosterone similarly induced these activities and glucocorticoids did not affected the isozyme patterns induced by the other two hormones.

Regulation of the secretory process of granular components from the convoluted tubular cells of the mouse submandibular gland

Autonomic regulation of the secretion of granule components in the convoluted tubular cells of male mouse submandibular glands was investigated with the use of an agar gel diffusion test using an antisera for male specific components. Whereas the injection of neither a parasympathomimetic agent (pilocarpine) nor a beta-adrenergic agent (isoproterenol) decreased the amount of the components in the glands, the injection of alpha-adrenergic agents (norepinephrine or phenylephrine) significantly decreased the amount of male specific components. Phenoxybenzamine, an alpha-blocker, completely inhibited these actions of norepinephrine and phenylephrine. These facts suggest that the alpha-adrenergic receptor participates in the secretion of male specific components present in the granules in the convoluted tubular cells of mouse submandibular glands.

Precocious induction of secretory granules by hormones in convoluted tubules of mouse submandibular glands

Precocious differentiation of convoluted tubules of the submandibular glands of mice was induced by daily injection of thyroxine, insulin, hydrocortisone and 5alpha-dihydrotestosterone from day 4 after birth. This treatment induced enlargement of the tubules and synthesis of secretory granules in the tubules. Treatment with 5alpha-dihydrotestosterone alone had no effect on enlargement of the tubules or synthesis of the granules. These findings suggest that, besides androgenic hormones, these three hormones are also involved in synthesis of granules in developing mice.

Binding protein for 5 alpha-dihydrotestosterone in mouse submandibular gland

The changes in the levels of the binding protein for 5 alpha-dihydrotestosterone in cytoplasmic extract of the submandibular glands during development were compared in male and female mice using a DEAE-cellulose filter assay. The binding protein was first detectable 5 days after birth in both sexes, at a time coincident with androgen-independent cytodifferentiation of the convoluted tubular cells in the submadibular gland. The level of the binding protein in female mice was maintained at 5 pmol/mg protein after birth, whereas in males it began to decrease from 3 weeks after birth with inccrease in serum testosterone, becoming much less than a quarter of the level in females or immature mice by 4 weeks after birth. However, after castration, the level of detectable binding protein in mature male mice increased within 7 days to the same level as that in females or immature mice. This suggests that the low binding capacity for exogenous hormone in mature male mice is due to occupancy of the binding sites by endogenous hormone.

Immunocytochemical localization of nerve growth factor (NGF) in the submandibular gland of adult mice by light and electron microscopy

Nerve growth factor (NGF) was localized in the submandibular gland of adult male mice by a direct immunocytochemical method using highly purified antibodies against NGF coupled to horseradish peroxidase. In light microscopic sections the reaction product was entirely confined to the cells of the secretory tubules. The acinar part of the gland was free of reaction product. This finding was confirmed by electron microscopy. Within the cells NGF was localized exclusively in the apical secretory granules. No reaction was observed in the rough endoplasmic reticulum, the Golgi region or in the granules of the basal part of the cells. This observation favours the assumption that NGF is derived from a precursor molecule and that the precursor is transformed into immunologically active NGF within the secretory granules during their transport from the basal to the apical part of the tubular cells. Stimulation of the submandibular gland with carbachol (2 mg/kg) led to a massive release of the content of the secretory granules, including NGF, into the salivary duct.

Morphological studies on the synthesis of secretory granules in convoluted tubules of mouse submandibular gland

The synthesis of zymogen-like secretory granules in convoluted tubules of mouse submandibular gland (SMG) was investigated by histometry, light microscopy and electron microscopy. In normal males secretory granules in the SMG increased greatly from 25 days after birth and reached a maximum level 50 days after birth. Castration of adult male mice markedly decreased the level, but it was completely restored by testosterone administration. A parallel was found between change in the granule level and the amount of rough endoplasmic reticulum (RER) in the convoluted tubular cells during development or after various treatments. Development of the Golgi apparatus was also observed in the cells when the granules increase. Both the increase in the granules and in the RER induced by testosterone were prevented by actinomycin D or puromycin. These results indicate that the granule contents are synthesized on the RER under the control of testosterone, and then condensed in the Golgi apparatus.