To determine the in¯uence of the myocardial infarction (MI) on bradykinin B1-receptor (B1R) regulation, we studied its expression in the left ventricle (LV) after MI. Rats were submitted to a permanent occlusion of the left coronary artery. Six hours, 24 h and 6 days after MI or after sham operation, left ventricular pressure (LVP) and dP/dt max were measured. LV-total RNA was extracted and B1R expression was analysed by a RNase-protection assay (each group n=6). LVP and dP/ dt max were impaired at all time points after MI. Basal B1R expression was not detectable in controls. Six hours after MI, the B1R expression was upregulated and reached a maximum 24 h after MI (4 fold vs 6 h). Six days post-MI, B1R expression returned to levels found 6 h after MI. These data are the ®rst demonstration for an induced myocardial B1R expression in an in vivo model of MI.

We conclude that myocardial ischaemia triggers B2-receptor up-regulation in both the infarcted and non-infarcted areas of the heart.

Since the 1940s, numerous cases of non-insulin-dependent diabetes mellitus (NIDDM) have been observed in certain American Indian populations. Extremely high prevalence rates of NIDDM occur most strikingly in several tribes of Paleo-Indians, whose ancestors migrated to North America greater than 11,000 yr ago. Archaeological evidence from that period indicates that certain groups of Paleo-Indians maintained an arctic-like hunter-gatherer life-style in an area in temperate North America ranging from Wyoming to Arizona. This life-style featured a reliance on unpredictable big game species as a major food source. However, at this time, big game species were becoming extinct. It is hypothesized that those Paleo-Indians who relied on big game as a food source developed a "thrifty" genotype that allowed a selective advantage during the periods of fasting that occurred between big game kills. It also is hypothesized that this thrifty genotype in these Indians may contribute to NIDDM when a sedentary life-style is adopted and food sources are constant. Because insulin resistance in muscle is a major feature of NIDDM, it is possible that insulin resistance per se is the phenotypic expression of the thrifty genotype.

The fire areas—or hearths—of the California Channel Islands, especially Santa Rosa Island, may be the oldest evidence of man in the Americas. The brick-red fire areas, dated at more than 40,000 years to 10,000 years ago, often contain charred mammoth bone and, rarely, possible stone tools. Though some of the fire areas may be hearths, recent research indicates that natural fires produce similar fire areas. Burned tree stumps and roots can redden the adjacent soil and resemble hearths. It is likely that most of the Pleistocene fire areas were caused by burned vegetation.