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N P Hodson

Publications and source records attributed to N P Hodson.

6 recordsLinked to original sources
PubMed1988

Pathological changes in the brain in equine grass sickness.

Lesions in a wide range of cranial nuclei are described in 11 horses with grass sickness. Similar changes were seen in one horse with laminitis, but not in control animals. It is suggested that such lesions are non-specific in nature.

Animals↗
PubMed1986

The sympatho-adrenal system and plasma levels of adrenocorticotropic hormone, cortisol and catecholamines in equine grass sickness.

Plasma levels of adrenocorticotropic hormone (ACTH), cortisol and catecholamines were used to study the role of the sympatho-adrenal system in equine grass sickness. Statistical evaluation determined differences of hormone levels between seven horses with grass sickness (one acute, five subacute and one chronic), six horses with colic (one with laminitis) and 16 control horses before and after mild stress. Plasma levels of the hormones were higher in horses with acute and subacute grass sickness than in the other groups. No differences were detected between horses with colic and stressed control horses but some hormone levels differed between control and colic horses and control horses before and after stress. It is possible that hyperactivation of the sympatho-adrenal system is caused by stress but it is uncertain whether the stress is only a result of the severity of the disease or also plays a role in its aetiology.

Acute Disease↗
PubMed1986

Occurrence, distribution and origin of peptide-containing nerves of guinea-pig and rat male genitalia and the effects of denervation on sperm characteristics.

A systematic immunohistochemical and radio-immunological survey of the occurrence, distribution and origin of the peptidergic nerve supply in guinea-pig and rat male genitalia is presented. Neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), substance P and CGRP were detected in the genital organs of both species. The densities and distribution patterns of the peptidergic nerves were compared with those of the adrenergic nerves, as revealed by antibodies raised against dopamine-beta-hydroxylase (D beta H) and tyrosine hydroxylase (TH), and the general neuronal component, as revealed by antibodies raised against neurofilament proteins (NF). Bilateral transection of the hypogastric nerves, in the guinea-pig, resulted in a decrease of substance P-containing nerves in the vas deferens and of NPY-, PHI- and VIP-containing nerves in the seminal vesicle. Unilateral disconnection of the pelvic nerves caused a decrease of VIP, PHI, substance P and CGRP nerve supply in the ipsilateral vas deferens and cauda epididymidis in the guinea-pig. A marked reduction of noradrenergic and NPY-containing nerves was observed in the vas deferens and sexual accessory glands of rats, chemically sympathectomised by chronic injection of low doses of guanethidine. Conversely, increase of substance P and CGRP immunoreactivities were observed, particularly in the vas deferens. After guanethidine, the cauda epididymidis and vas deferens were distended with spermatozoa, suggesting paralysis of the ducts. Spermatozoa had a decreased percentage of attached cytoplasmic droplets, indicating prolonged retention in the ducts.

Animals↗
PubMed1984

The regulatory peptide system of the large bowel in equine grass sickness.

In recent years, distinct changes in regulatory peptides have been found in a number of gastrointestinal diseases. Grass sickness is a fatal disease of horses for which the etiology has yet to be fully ascertained. In this study, the peptide-containing nerves and ganglionic and mucosal endocrine cells of the ileum, colon and rectum were investigated in horses with sub-acute or chronic grass sickness and compared with normal controls using immunocytochemistry, at both the light and electron microscopical levels, and radioimmunoassay. A substantial loss of both peptide-containing cells and nerves was found in all of the sick horses, particularly in the ileum. Electron microscopy revealed marked degeneration of nerves in the gut wall. Fibers containing granules immunostained for substance P or VIP, using the immunogold staining technique, underwent extensive degranulation in grass sickness, with the formation of multiple vacuoles. Radioimmunoassay of peptide content also showed that the most drastic changes occurred in the ileum. For example, VIP content was significantly reduced from 109 +/- 19.8 (mean +/- SEM) pmoles/g in controls to 6.8 +/- 1.4 pmoles/g in grass sickness (p less than 0.001) and substance P from 65.9 +/- 8.1 to 31.3 +/- 9.5 (p less than 0.02). These results may have applications in the diagnosis and treatment of grass sickness.

Animals↗