Schulze W
Histochemistry. 1982;75(1):133-43. doi: 10.1007/BF00492540.
The effects of different preparative and cytochemical procedures on adenylate cyclase (AC) activity in heart muscle homogenates were studied by quantitative analysis. We were mainly concerned with perfusion prefixation, using glutaraldehyde (GA) with and without DMSO, and with the influence of cytochemical incubation with lead ions as the capture reagent. Furthermore, we measured the direct effect on the AC activity of lead, cobalt, and strontium ions in prefixed heart homogenates. We also studied the influence of phosphatidylinositol and 2',5'-dideoxyadenosine. The following results were obtained: 1. Perfusion fixation using 2% GA buffered with cacodylate reduced the AC activity by about 20%. After the entire cytochemical procedure was finished, 20% of the original AC activity was still present. Stimulation by epinephrine, histamine and fluoride, which increased the activity of AC two or three times in our experiments, was only slightly reduced by the cytochemical treatments. 2. Lead ions (2 mM), added to the biochemical assay without chelating compounds, reduced the AC activity about 90%. 5 muM phosphatidylinositol stabilized the fluoride- and hormone-sensitive AC activity. 3. Co2+ also reduced the AC activity, though less than Pb2+. Sr2+ had no effect on the basic activity of the AC but had a slightly inhibitory effect on the hormone and fluoride stimulation. 4. 5% DMSO added to the fixative had no influence on the basic activity of the AC. However, this solvent definitely reduced the level of stimulation by fluoride and guanine nucleotide plus hormones. 5. A potential inhibitor of enzyme activity and of the hormone- and fluoride-sensitive AC was the adenosine derivative, 2',5'-dideoxyadenosine. This compound, at a concentration of 10(-3) M, inhibited all AC activity in the heart homogenates.
通过定量分析研究了不同制备和细胞化学程序对心肌匀浆中腺苷酸环化酶（AC）活性的影响。我们主要关注使用含和不含二甲基亚砜（DMSO）的戊二醛（GA）进行灌注固定，以及以铅离子作为捕获试剂进行细胞化学孵育的影响。此外，我们测量了固定后的心脏匀浆中铅、钴和锶离子对AC活性的直接影响。我们还研究了磷脂酰肌醇和2',5'-二脱氧腺苷的影响。得到以下结果：1. 使用用二甲胂酸盐缓冲的2% GA进行灌注固定使AC活性降低约20%。在整个细胞化学程序完成后，仍保留原始AC活性的20%。在我们的实验中使AC活性增加两到三倍的肾上腺素、组胺和氟化物刺激，仅因细胞化学处理而略有降低。2. 在没有螯合化合物的情况下添加到生化测定中的铅离子（2 mM）使AC活性降低约90%。5 μM磷脂酰肌醇稳定了对氟化物和激素敏感的AC活性。3. Co2+也降低了AC活性，尽管比Pb2+的作用小。Sr2+对AC的基础活性没有影响，但对激素和氟化物刺激有轻微抑制作用。4. 添加到固定剂中的5% DMSO对AC的基础活性没有影响。然而，这种溶剂确实降低了氟化物和鸟嘌呤核苷酸加激素的刺激水平。5. 酶活性以及对激素和氟化物敏感的AC的一种潜在抑制剂是腺苷衍生物2',5'-二脱氧腺苷。该化合物在浓度为10(-3) M时抑制心脏匀浆中的所有AC活性。
