Asian Journal of Experimental Sciences





Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 1-7


Mechanisms of Platelet Aggregation and the Anti-aggregatory Effect of Human Plasma

Sheikh A. Saeed and Anwar-ul-Hassan Gilani
Department of Pharamcology,
The Aga Khan University Medical College,
Karachi, Pakistan.


There are many possible biochemical and physiological pathways of human platelet aggregation. The three most studied pathways are: release of ADP; the liberation and metabolism of arachidonic acid; and the synthesis of platelet activating factor (PAF). Each of these pathways generates compounds which act as intracellular mediators to propagate the rapid activation resulting in platelet aggregation. On the other hand, the discovery that human blood plasma possesses the ability to inhibit platelet aggregation has led to the suggestion that there exists one or more circulating inhibitor(s) of platelet aggregation named EIPA. The unraveling of EIPA has significant implications for therapeutic intervention in pathological states as well as for the understanding of platelet physiology.



Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 8-13


Endogenous Inhibitor of Human Platelet Aggregation: Purification and Possible Identity

Anwar-ul-Hassan Gilani and Sheikh A. Saeed
Depatment of Pharmacology,
Faculty of Health Science,
Karachi, Pakistan

We previously reported that human plasma inhibits platelet aggregation induced by arachidonic acid in a concentration-dependent manner and postulated that human blood may contain one or more inhibitor(s) of platelet aggregation. We now report that the inhibitor(s) is proteinaceous in nature because boiling or deproteinization of plasma with trichloracetic acid abolished inhibitory activity. The analysis of plasma Cohn fractions revealed that the inhibitory activity was associated with a-globulin and albumin-rich protein fractions of plasma. On specific removal of albumin from plasma by affinity chromatography, the platelet aggregation inhibitory activity was reduced by 70%. These results indicate the presence of endogenous inhibitor(s), one of which is associated with albumin, in plasma.


Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 14-20


A Univentricular Heart and its Conduction System in AC Triloculare Biatriatum with a Right Outlet Chamber


C. J. van Nie
Department of Anatomy and Embryology,
Medical Faculty, Free University,
Van de Boechorstraat 7, 1081 BT Amsterdam,
The Netherlands.

A univentricular heart with normal1y related great arteries of a calf is described. The histological search for the localization of the conduction system leads to the conclusion that the described univentricular heart belongs morphogically in fact to the group of hearts with a hypoplastic right ventricle, while the atrioventricular node, the common bundle and its branches are localized normally in the muscular right apical border of the interventricular defect. Some bizarre coursing cardiac heart fibres have been observed too. Their genesis and function remains unknown.



Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 26-34


Hormonal/Antihormonal Profile of Butanolic Extract of Pueraria tuberosa DC


R. Mathur Sangeeta Shukla, A. Mathur and A. O. Prakash
Laboratory of Reproductive Biology,
School of Studies in Zoology,
Jiwaji University, Gwalior - 474011

Investigations on a butanolic extract of Pueraria tuberosa DC. (tubers) for various hormonal/antihor­monal activities revealed its estrogenic action when assayed in bilateraily ovariectomized rats. At a higher dose, administration of the extract together with diethylstilbestrol, antagonized the latter’s estrogenic effect. The extract’s estrogenic activity was also demonstrated by its ability to induce delayed implantation in ovariectomized, progesterone treated rats. The extract also exhibited a mild progestational effect.


Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 27-35


Histochemical Picture of the Corpus Allatum Of Supella supelle­ctilium Serville (Blattoidea; Blatellidae) and some Observations on the Possible Mode of Origin of The CA - Secretion


S. C. Phatak
Department of Biological Sciences,
Rani Durgavati University, Jabalpur - 482001

The secretory cells of the corpus allatum of S. supellectillium exhibit some variations with respect to their protein, lipid and RNA contents, during various stages. In the nymphs, the variation appears to be related to the process of moulting. All the three particularly the lipids and RNA are markedly higher in the intermoult period and are very low during the process of ecdysis. In the adults also, the protein content is higher in the active stages but is markedly lesser in the inactive glands. The variation in the lipid and RNA contents is more pronounced and these are unusually high in the active glands. The carbohydrate content is always poor, throughout the life. The relevance of these observations with regard to the secretion cycle of the gland and the possible mode of origin of the CA secretion have been discussed.



Asian J. Exp. Sci., Vol. 4, No. 1, 1988; 36-44


Adrenergic and Cholinergic Receptors in the Isolated Scale Melanophores of a Teleostean Fish Cirrhinus Mrigala (Ham.)


Mohd. Ovasis and Arun K. Gorakh
Department of Biosciences,
Barkatullah University, Bhopal - 462026 (M.P.)

Melanophores of Cirrhinus mrigala were dispersed in response to adrenaline, isoprenaline and low doses of dopamine. Phenylephrine and high doses of dopamine aroused a marked aggregation in the fish melanophores. Acetylcholine, carbachol, pilocarpine and nicotine induced a dispersal effect on the melanophores. Physostigmine per se dispersed the melano­phores. Atropine and scopolamine failed to block the dispersal effects of cholinergic agonists, while nicotine blocked the dispersal effect of carbachol. Hexamethonium and atropine per se aggregated the C. mrigala melanophores. It is concluded that in Cirrhinus mrigala melanoph­ores two different types of adrenergic receptors may be present i.e., alpha aggregatory and beta dispersal in nature. Results of cholinergic drugs indicate the involvement of cholinergic nicotinic receptors in the dispersal responses of melanophores in this fish species.