The subcellular morphology of avian adrenal medulla

Abstract

The electron microscopic study of the avian adrenal medulla have shown that in most birds, the epinephrine and norepinephrine cells can be differentiated based on the morphology, size, opacity and the fine structures of their granules. However, the functional characterization of some medullary cells, other than epinephrine and norepinephrine remains unresolved to this date. Among the avian adrenals studied, it is only in the domestic fowl that the separate cellular origin of epinephrine and norepinephrine cells have been established.Earlier studies on the manner of release of secretory granules from the adrenal catecholamine storing cells in birds have led one to infer that exocytosis is only mode of discharge of granules. Surprisingly this is not apparent in some of the reports obtained in recent years. Hence the release mechanism of the adrenomedullary hormones need to be further explored ultrastructurally.

Molecular Orbital and Density Functional Study of the Formation, Charge Transfer, Bonding and the Conformational Isomerism of the Boron Trifluoride (BF3) and Ammonia (NH3) Donor-Acceptor Complex

“…It is also stated that the density functional quantities are independent of molecular orbital scheme [38]. Ghosh [10,39] has established that if the CNDO/2D formalism is invoked for the calculation of charge rearrangement during donor acceptor interaction, the result is reliable and the trend of charge rearrangement computed through the CNDO/2D method is quite comparable to that of ab-initio methods. It is reported [26,40] that Pople's CNDO method [41] can compute accurate conformational isomerism of molecules.…”

“…In view of the above we have adopted CNDO/2 method of Pople and co-workers in the present study. However, the charge rearrangement is not computed through CNDO/2 formalism, but through CNDO/2D formalism which is obtained by simply incorporating the Löwdin's [10,39,42] deorthogonalization technique into the CNDO/2 program. Standard parameters [41] and STO basis set have been used; the coulomb and the overlap integrals are computed through the explicit analytical formulae laid down by Roothaan [43].…”