Metabolic responses following isoproterenol-induced myocardial infarction in arteriosclerotic breeder vs. non-arteriosclerotic virgin and ovariectomized female rats.

Intact and ovariectomized, non-arteriosclerotic female rats and arteriosclerotic, breeder female rats were subjected to myocardial infarction by the administration of 2 subcutaneous injections, 24 hr apart, of the beta-adrenergic stimulator, isoproterenol. The animals were sacrificed at regular hourly intervals following each injection and then on days 4, 6, 8, 10, 12, and 16 thereafter. Measurement of serum insulin and free fatty acids (FFA) demonstrated a blunted response in these metabolic parameters in the case of the ovariectomized virgin rats. The non-arteriosclerotic, intact virgin rats exhibited dynamic changes in serum insulin, glucose, FFA and corticosterone (Cmpd. B) following both isoproterenol injections, whereas the arteriosclerotic breeder rats manifested elevated levels of these parameters on Day 1, but did not display any increases in serum levels, except for FFA, following the second isoproterenol injection on Day 2. In spite of the hormonal alterations brought about by the gonadectomy and their differing metabolic response, the ovariectomized females did not have a mortality rate significantly different from the intact females. Thus, the presence or absence of ovarian estrogens seemingly does not affect the progress of an isoproterenol-induced myocardial infarction.     

The diagnosis and management of temporal arteritis

Temporal arteritis (TA), or giant cell arteritis, is a systemic autoimmune vasculitis affecting patients over 50 years of age. It can cause rapid, irreversible bilateral vision loss in older adults and is therefore considered an ophthalmological emergency. Many of the symptoms and signs of TA can be vague, non-specific and gradual in onset, often leading to a delayed or inaccurate diagnosis. As such, it is important for a wide variety of primary optometrists and health practitioners to maintain a robust understanding of the clinical presentation, key investigations and time-sensitive management of this disease, as early initiation of treatment for TA can be vision- and life-saving.