Mäepea O, Nilsson S F
Department of Phsiology and Medical Biophysics, Uppsala Biomedical Center, Sweden.
Curr Eye Res. 1991 Aug;10(8):703-12. doi: 10.3109/02713689109013864.
The effect of increased intraocular pressure (IOP) on stimulated aqueous humor flow (AHF) was studied in cynomolgus monkeys. Two experimental series were performed, one with unilateral VIP-treatment (60 micrograms intracamerally) and one with unilateral terbutaline-treatment (10 micrograms.ml-1 perfusion fluid). The AHF was determined with a labelled albumin dilution method, and an artificial increase in IOP was produced by clamping the outlet of the perfusion system, thus causing a net inflow of perfusion fluid. The initial AHF was significantly higher in the VIP-treated eye than in the control eye - 1.568 +/- 0.095 as compared to 1.112 +/- 0.103 microliters.min-1 (P less than or equal to 0.01). The spontaneous IOP was 5.8 +/- 0.4 mmHg (P less than or equal to 0.001) higher in the VIP-treated eye. There was no difference in pseudofacility between the VIP-treated eye (0.063 +/- 0.016 microliter.min-1.mmHg-1) and the control eye (0.065 +/- 0.022 microliter.min-1.mmHg-1), but the total and true outflow facilities were higher in the VIP-treated eye. In the experiments with terbutaline, the initial AHF was 1.729 +/- 0.114 for the experimental eye and 1.262 +/- 0.104 microliters.min-1 for the control eye (P less than or equal to 0.01). The pseudofacility tended to be higher in the terbutaline-treated eye (0.072 +/- 0.026 microliters.min-1.mmHg-1) than in the control eye (0.048 +/- 0.012 microliters.min-1.mmHg-1), but the difference was not statistically significant. There was no difference in total and true outflow facility between the experimental and control eye. The results indicate that the pressure sensitivity of the AHF is independent of the initial level of the AHF. VIP increases true outflow facility, possibly via a direct effect on the trabecular meshwork. VIP also appears to rise the IOP due to an increase in episcleral venous pressure, which could be secondary to vasodilatation in the anterior segment.
在食蟹猴中研究了眼内压（IOP）升高对刺激房水流出（AHF）的影响。进行了两个实验系列，一个是单侧VIP治疗（前房内注射60微克），另一个是单侧特布他林治疗（灌注液中含10微克·毫升-1）。采用标记白蛋白稀释法测定AHF，并通过夹住灌注系统的出口人为升高IOP，从而导致灌注液净流入。VIP治疗眼的初始AHF显著高于对照眼——分别为1.568±0.095微升·分钟-1和1.112±0.103微升·分钟-1（P≤0.01）。VIP治疗眼的自发IOP高5.8±0.4 mmHg（P≤0.001）。VIP治疗眼（0.063±0.016微升·分钟-1·mmHg-1）与对照眼（0.065±0.022微升·分钟-1·mmHg-1）之间的伪房水流畅度无差异，但VIP治疗眼的总房水流出率和真房水流出率较高。在特布他林实验中，实验眼的初始AHF为1.729±0.114微升·分钟-1，对照眼为1.262±0.104微升·分钟-1（P≤0.01）。特布他林治疗眼（0.072±0.026微升·分钟-1·mmHg-1）的伪房水流畅度倾向于高于对照眼（0.048±0.012微升·分钟-1·mmHg-1），但差异无统计学意义。实验眼与对照眼之间的总房水流出率和真房水流出率无差异。结果表明，AHF的压力敏感性与AHF的初始水平无关。VIP可能通过对小梁网的直接作用增加真房水流出率。VIP似乎还因巩膜静脉压升高而使IOP升高，这可能继发于前段血管扩张。
