The cellular composition of the adrenal medulla of sexually mature guinea pigs

The adrenal glands from 15 guinea pigs aged 90 days were used in the study. Paraffin slices were stained with Mayer haematoxylin and eosin with Masson method and silvered. The histochemical reactions were carried out for catecholamines and the biochemical determinations of catecholamines. Ultrastructural observations were also performed. In the adrenal medulla of sexually mature guinea pigs numerous epinephrocites and no noreoinefrocites were observed when histochemical methods were used. The small and large ganglion cells accompanying the supporting and neurolemmal cells formed typical gangliar weaving (medullary ganglia). Apart from epinephrocytes, small and large ganglion cells and supporting and neurolemmal cells, small intensively fluorescent (SIF) cells were also detected. Biochemical investigation revealed that the mean content of adrenaline calculated for a pair of adrenal glands was 98.87% of the pool of catecholamines, whereas the mean content of noradrenaline was 1.00%, and of dopamine 0.13%

Immunolocalization of CGRP, NPY and PGP 9.5 in guinea pig skin

By means of immunoperoxidase and immune-alkaline phosphatase methods the immunoreactivities to neuropeptides: neuropeptide Y (NPY), calcitonin gene related peptide (CGRP) and a pan-neuronal marker, the protein gene product 9.5 (PGP 9.5), were evaluated in guinea pig deep dorsal skin specimens. CGRP immunoreactive (CGRP-IR) and NPY-immunoreactive (NPY-IR) nerve fibres were dispersed in the papillary dermis and sometimes inside the hair roots and among the sebaceous gland cells. Such localized nerve fibres have not so far been described. In the subcutaneous layer nerve trunks were found composed of CGRP-IR and NPY-IR nerve fibres. Some of these indicated vestigial or negative immunoreactivity to PGP 9.5