The distribution, morphological features, and morphometric characteristics of cell bodies producing oxytocin (OT) and vasopressin (AVP) were studied in the rabbit hypothalamus by means of a conventional immunoperoxidase method. The aim of the present study was to determine the existence or not of a species-specific OT-cell group that might be involved in the dense OT innervation of the intermediate lobe in the leporidae. No OT-cell group clearly distinct from the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei was found, even in colchicine-treated animals. Most immunoreactive perikarya were found within these nuclei. In addition, small AVP neurons occurred in the suprachiasmatic nucleus. In the SON, the predominant, tightly packed AVP cells occupied the ventral part of the nucleus, whereas OT neurons were dorsolaterally located. The PVN presented a loose organization without any obvious subdivision. OT cells, which predominated, occupied the medial part of the nucleus. The PVN had a prominent rostral anterobasal extension composed mainly of OT cells. Laterally to the nucleus, numerous large AVP neurons, with few and smaller OT cells, dispersed along the neurosecretory tract without forming definite cell clusters. AVP cell bodies had a rough granular aspect contrasting with the smooth and fine one of OT cells. Spinelike processes were rarely observed on the perikarya, except on large scattered AVP neurons, but frequently covered the proximal dendrites of both types of neurons. Throughout the hypothalamus, OT neurons had definitely smaller mean somal areas and were more homogeneous in size than AVP cells.

Animals↗

PubMed1989

Risk factors for myocardial infarction during coronary artery bypass graft surgery.

Patients with a particular thrombotic profile may be at greater risk of myocardial infarction during coronary artery bypass graft surgery. The thrombotic profile of 50 patients admitted to hospital with stable angina pectoris was determined prior to haemodynamic investigation. ECG results and determination of cardiac enzymes showed that 12 patients had suffered a perioperative myocardial infarction. These patients had a higher mean atherosclerotic score (42.1 +/- 10.5 vs 32.9 +/- 13, P less than 0.02), a longer aortic cross clamp time (59 +/- 15.2 vs 45.7 +/- 16.3 min, P less than 0.05), lower serum levels of protein C (101.2 +/- 26 vs 124.7 +/- 31.4%, P less than 0.05) and tissue plasminogen activator (322 +/- 580 vs 2307 +/- 2830 IU ml-1, P less than 0.01). There were no differences between the two groups in Jenkin's coronary score, the number and type of grafts, ejection fraction, left ventricular end-diastolic pressure, lipid profile or levels of markers of platelet release. In addition to a more severe distal coronary atheroma and a longer aortic cross-clamp time, patients with impaired endothelial fibrinolytic activity appeared to be at greater risk of myocardial infarction during coronary artery bypass graft surgery.

Aged↗

PubMed1989