Journal of Endocrinology and Reproduction

A. A. Nerkar ¹, M. M. Gadegone ¹

Affiliations
1 Department of Zoology, Institute of Science, Nagpur (MS)-440001, IN

Abstract

Follicular colloids were examined in pituitary gland of Indian bat, Rhinopoma hardwickei hardwickei during annual reproductive cycle. Colloids were distributed throughout the pars distalis, pars intermedia and pars tuberalis. The colloid droplets were round or oval in shape. In some colloids outer border was irregular. These droplets were of various sizes and many of them were vacuolated. Pituitary colloids were observed during the different stages of the reproductive cycle. No change in number, size and shape was observed during anestrus, oestrus, and early pregnancy. At mid- and late pregnancy the number and size of colloid droplets increased. The increasing trend in number and size of colloid droplets was continued during early lactation also. At late lactation, colloid masses showed decrease in number and size. More colloid masses were observed in male pituitary than those observed in the female pituitary.

Keywords

Bat, Pituitary Colloid, Reproductive Cycle.

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A. A. Nerkar ¹, Y. T. Kubde ¹, M. M. Gadegone ¹

Affiliations
1 Department of Zoology, Institute of Science, Nagpur-440001, IN

Abstract

The anterior pituitary gland (pars anterior) of the bat Taphozous kachhensis was examined cytochemically by employing several cytochemical staining techniques. Six cell types could be recognized, on the basis of their morphological characteristics and tinctorial properties, viz., two types of non-mucoid (acidophilic) STH and LTH, and three types of mucoid (basophilic) TSH, FSH and LH cells; the sixth, ACTH cells, were amphophilic. The cells are arranged in follicles or acini, separated from each other by a thin layer of connective tissue. The non-mucoid cells are much more concentrated in the postero-lateral and postero-median regions of the pars distalis. ACTH and TSH cells are mostly localised in large numbers in the peripheral region of the pars distalis. FSH cells are concentrated towards the antero-lateral, anterior and median regions. LH cells are distributed throughout the pars anterior but are more abundant towards the posterior and lateral regions. The probable role of these cell types in the physiology of reproduction of this bat is discussed.

Keywords

Anterior Pituitary Gland, Bat, Cytochemistry, Reproductive Cycle.

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A. A. Nerkar ¹, M. M. Gadegone ¹

Affiliations
1 Cell Biology Section, Department of Zoology, Institute of Science, Nagpur – 440001, IN

Abstract

The paper describes the ultrastructural organization of the corpus luteum of the emballonurid bat, Taphozous longimanus (Hardwicke). This bat is continuously asychronous breeder, exhibiting aseasonal polyoestry. During the early part of gestation, the luteal cells are compactly arranged with clearly demarcated boundaries, and show only moderate hypertrophy. Ultrastructural study of luteal cells during early pregnancy reveals the presence of irregularly shaped euchromatic nucleus, rod-shaped mitochondria with tubular or vesicular cristae, numerous lipid droplets and profiles of smooth/agranular endoplasmic reticulum in the form of short tubules or vesicles. The close association of mitochondria with lipid droplets and agranular endoplasmic reticulum in the luteal cells suggests that these cells are actively involved in steroidogenesis. During mid-pregnancy, the luteal cells are hypertrophied and are highly vacuolated. Large number of hypertrophied mitochondria, increased profiles of tubular cisternae of smooth endoplasmic reticulum and abundant lipid droplets in the cytoplasm of luteal cells during mid-pregnancy indicate an increase in the steroidogenic activity.

Keywords

Bat, Corpus Luteum, Luteal Cells, Progesterone, Pregnancy.

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A. F. Shireen Iqbal ¹, A. A. Nerkar ²

Affiliations
1 Department of Zoology, St. Francis De’Sales College, Nagpur − 440006, Maharashtra,, IN
2 Reproductive Biology Section, Department of Zoology, Government Institute of Science, Nagpur − 440008, Maharashtra., IN

Abstract

The present paper describes the fine structural characteristics of the adrenal-cortical region of adult male fruit bat Rousettus leschenaulti. The functional significance of the secretions of the adrenal-cortical region in reproduction is discussed. This study was carried out in the Indian fruit bat R. leschenaulti (Desmarest) because of the unique aspects of reproduction of this animal. It shows two breeding cycles, one in the autumn and the other in the spring. The adrenal gland of Rousettus undergoes remarkable cyclical changes in relation to the reproductive cycle. The cortex and medulla are clearly demarked. During the inactive and pre-breeding period, the zona glomerulosa is made up of polyhedral cells arranged in the form of acini. On the other hand during the breeding period it is highly vascularized. It is composed of compactly arranged dark and light polyhedral cells. Smooth endoplasmic reticulum in the form of circular vesicles, is well developed during breeding phase. The zona fasciculata is a larger zone in the cortex. During inactive period, it is made up of polyhedral cells and during pre-breeding and breeding periods cells are polygonal in shape with spherical nucleus. The zona fasciculata is richly vascular during the breeding period. The cells of zona fasciculata during the breeding period have prominent smooth endoplasmic reticulum. Mitochondria, with tubular and vesicular cristae and a large number of lipid droplets, suggest increased rate of synthetic activity. The close association of smooth endoplasmic with mitochondria and lipid droplets indicate that these cells are actively involved in steroid biosynthesis. Steroidogenic organelles are well developed in the cells of reticularis during the inactive prebreeding and active breeding period. All these organelles suggest that cells of glomerulosa are active in synthesizing steroid hormones. The cisternae of smooth endoplasmic reticulum lie close to the nucleus, mitochondria and lipid droplets. This association most likely represents the conversion of steroids to lipid droplets for storage or the reverse trend indicates removal of sterol for steroidgenesis.

Keywords

Adrenal Cortex, Bat, Reproductive Cycle

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