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W Montgomery

Publications and source records attributed to W Montgomery.

27 records · Page 2Linked to original sources
PubMed1984

Pharmacology and inotropic potential of forskolin in the human heart.

We evaluated the effects of the diterpene compound forskolin in human myocardial adenylate cyclase preparations, isolated trabeculae and papillary muscles derived from failing human hearts, and acutely instrumented dogs. Forskolin was a potent, powerful activator of human myocardial adenylate cyclase and produced maximal effects that were 4.82 (normally functioning left ventricle) and 6.13 (failing left ventricle) fold greater than isoproterenol. In contrast to isoproterenol, forskolin retained full activity in membrane preparations derived from failing hearts. In cyclase preparations, forskolin demonstrated unique substrate and Mg2+ kinetic properties that could be distinguished from hormone receptor-coupled agonists or fluoride ion. The adenylate cyclase stimulatory effect of forskolin was synergistic with isoproterenol, apparently due to the location of forskolin activation being beyond the level of hormone receptor-agonist in the receptor-cyclase complex. Forskolin was a potent positive inotrope in failing human myocardium, producing a stimulation of contraction that was similar to isoproterenol. Finally, in open chest dogs forskolin was a positive inotropic agent that reduced preload and afterload. We conclude that forskolin belongs to a class of agents that may have therapeutic potential in the treatment of congestive heart failure.

Adenylyl Cyclases↗
PubMed1982

Role of ventrolateral medulla in vasomotor regulation: a correlative anatomical and physiological study.

Two groups of experiments were carried out in rabbits. First, the ventrolateral reticular formation of the medulla oblongata was stimulated either by microinjection of sodium glutamate solution (exciting only cell bodies) or electrically (exciting cell bodies and axons). This region has been shown previously to contain a dense and compact group of bulbospinal cells. The effects of both electrical and chemical stimulation of specific sites were correlated with the density of ventrolateral bulbospinal cells at the same sites. Glutamate microinjection into the center of the group of bulbospinal cells elicited a very large and sustained increase in arterial pressure, whereas microinjection into sites outside this region elicited a very small or no response. These results suggest that it is the bulbospinal ventrolateral cells which mediate the pressor response to glutamate stimulation. Focal electrical stimulation in the ventrolateral medulla elicited increases in arterial pressure and decreases in femoral and renal vascular conductance, as well as a short-latency increase in renal sympathetic nerve activity. The most effective sites for focal electrical stimulation lay within the region of greatest density of bulbospinal cells; slightly less effective sites lay just rostral and caudal to this region. It is suggested that stimulation in these latter sites predominantly excites axons of passage. Secondly, the origin of afferent fibers to the ventrolateral vasomotor area was studied using the horseradish peroxidase (HRP) method. This revealed major projections from the medial part of the nucleus tractus solitarius and the parabrachial nucleus in the pons. The physiological and anatomical studies taken together are consistent with the hypothesis that the bulbospinal ventrolateral cells are vasomotor in function, and receive afferent inputs from brain stem nuclei which are known to play a role in autonomic regulation.

Adrenergic Fibers↗
PubMed1981

Cartilaginous tumors of the larynx.

Laryngeal cartilaginous tumors are well-defined masses that arise within the endolaryngeal structures, predominantly the cricoid cartilage. Twelve cases with long-term followup are reviewed. The importance of early and complete radiological evaluation and the potential for recurrence is emphasized. Since metastases or extralaryngeal extension is rare, conservative surgery, preserving laryngeal function as long as possible, is the treatment of choice. The histological distinction of chondroma versus chondrosarcoma is not essential for the clinical management of these lesions, and we suggest they be designated as cartilaginous tumors of the larynx.

Adolescent↗
PubMed1976

Pathologic findings in gouty cricoarytenoid arthritis.

The clinical manifestations of cricarytenoid joint gouty arthritis have been previously reported. They include hoarseness, dysphagia, and dysphonia. Exacerbation of gouty laryngeal arthritis can accompany multiple joint involvement or appear as a single joint manifestation. The development of laryngeal symptoms in the patient with arthritix calls for prompt indirect laryngoscopy. The phonatory and sphincteric functions of the larynx are severely altered by limited cricoarytenoid joint fixations.

Aged↗