Histochemical and biochemical studies on esterase activity in the rat ovary

A correlative histochemical and biochemical study has been made of the changes in esterase positive sites in immature (10-, 20- and 30-days old), mature normal cycling (3-, 5- and 8-months-old), pregnant and lactating rat ovaries. The typical perivascular esterase-positive sites localized in the hilar portion, branch along the blood vessels and traverse into medullary and cortical portions of the ovary. The stromal vascularity surrounding the normal developing follicles, corpora lutea, atretic follicles and interstitial gland tissue showed rich activity of this enzyme system. On semiquantitative basis the number, intensity and quantity of esterase-positive sites vary with the maturation and reproductive states of the rat. The administration of estradiol-17 beta increased the fine perifollicular and theca externa perivascular esterase-positive sites, whereas atropine and reserpine affected severely both the large and fine meshwork of esterase-positive sites. Biochemical estimates of acetylcholine esterase activity endorse these histochemical observations. The possible roles of AChE activity in varied ovarian functions are discussed.     

Envelope diversity, characteristics of V3 region and predicted co-receptor usage of human immunodeficiency viruses infecting north indians

Subtypes of human immunodeficiency virus type 1 circulating in 21 north Indian patients were characterized based on the partial sequence of the gp120 envelope protein. A majority of viruses (85.7%, 18/21) were subtype C, while 14.3% (3/21) were subtype A. Sequence analysis revealed that the V3 region was highly conserved compared with V4 and V5. The predicted use of co-receptors indicated exclusive usage of R5, except for two subtype A viruses (AIIMS279 and AIIMS281). Our results demonstrate conservation within the V3 loop of subtype C viruses, and suggest the emergence of non-clade C viruses in the north Indian population.     

Histochemical studies on eggshell formation in Paramphistomum cervi (Digenea: Paramphistomatidae)

The formation of the egg mass in the ootype, containing the oocyte, vitelline cells, numerous spermatozoa and Mehlis' gland secretion marks the beginning of eggshell formation. Mehlis' gland cells pour their lipoprotein secretion into the ootype; this secretion forms a thin template around the egg mass and upon this template the shell globules are deposited. Eggshell formation begins in the proximal uterus and is completed in the middle uterus. The eggshells are devoid of phenols and phenolase indicating that hardening is not by quinone tanning. The eggshells contain keratin and are stabilized by disulphide linkages.     

Gross morphology of ovarian changes during the reproductive cycle of Indian lizards (Calotes versicolor and Hemidactylus flaviviridis).

A comparative study has been made of the reproductive cycle and gross ovarian changes in two species of Indian lizards (Calotes versicolor and Hemidactylus flaviviridis), which are oviparous. They exhibit a single, short breeding season that extends over a few months. Calotes ovalutes 10 to 32 eggs per clutch (the highest number recorded so far for lizards belonging to the family Agamidae) from last week of June to the first week of September, with July through August being the months of highest reproductive potential when monsoon occurs. From October to May, there occur reduced ovaries containing small previtellogenic follicles which begin to increase in size with the approach of June when heavy yolk deposition occurs. Hemidactylus ovulates from mid-March to mid-May, with a peak in April when there occurs an appreciable increase in day length and temperature. It usually ovulates two eggs per clutch (one from each ovary). From June to the 3rd week of February, the ovaries remain small whitish bodies, each containing 3 or 4 small previtellogenic follicles of variable size which, with the approach of March, begin to increase in size by accumulating yolk. Various indirect evidences suggest that both the lizards lay more than one clutch of eggs during the breeding season.     

Histochemical observations on the lipid changes in the ovarian interstitial gland tissue of rats.

Lipid changes were studied histochemically in the ovarian interstitial tissue of untreated and hormone-treated rats during the oestrous cycle, pseudopregnancy, pregnancy and lactation. The hormones tested were LH, prolactin and oestradiol benzoate, alone or in combination. Conspicuous lipid changes occurred only in response to LH.     

Correlative morphological and cytochemical observations on the nucleoli and nuclear bodies during avian oogenesis.

A correlative morphological and cytochemical study has been made of the nucleoli and nuclear bodies in the growing oocytes of the crow (Corvus splendens) and common myna (Acridotheres tristis). The nucleoli show morphological and cytochemical changes during oocyte growth, which are described in detail. In young oocytes at diplotene stage, two to six nucleoli, which are attached to condensed diplotene chromosomes, show RNA, lysine-rich histones and some non-histones, the proteins contain S-S and SH groups. In subsequent stages of oocyte growth, the cortex of nucleolus also develops arginine-rich histones whereas the medulla shows lysine-rich histones. The significance of both morphological and cytochemical changes of nucleoli has been discussed in relation to oocyte growth. Seven types of nuclear bodies are described. They are composed of proteins and carbohydrates. Their shape, size and structure vary during different stages of oocyte growth. Finally, their material is transported into the ooplasm.     

Biochemical changes in lipids during follicular growth and corpora lutea formation and regression in rat ovary

A biochemical study has been made on quantitative and qualitative changes in lipids of small (less than 300 microns), medium (300 to 550 microns) and large (less than 550 microns) follicles and in the fully developed and regressing corpora lutea. The total lipid content increased in the growing follicles and corpora lutea. Phospholipids formed the major component of total lipids in small sized follicles and developed corpus luteum. The cholesterol amount increased with the growth of follicles but decreased in the developed and regressing corpora lutea. Glycerides were the main fraction of total lipids in regressing corpora lutea. Free fatty acids were present in minor quantities in the growing follicles and corpora lutea. The physiological significance of these lipid changes is discussed.