Animal-derived peptide preparations in rat hypoxia, behavior and blood studies
N. N. Karkishchenko, V. N. Karkishchenko, Kh. Kh. Semenov, G. D. Kapanadze, Yu. V. Fokin, O. V. Alimkina, A. O. Revyakin, O. I. Stepanova, E. L. Matveyenko, N. V. Kasinskaya, S. E. Dengina · 2013 · Biomeditsina. 2013;(1):6–15.
Indexed 2026-11-11.
Related evidence maps: Military & occupational ↗
Reported findings and study design
Reported findings
The methods give six female Wistar rats per group. Pep-1 through Pep-12 or saline was administered rectally once daily for 21 days. The article gives no dose, concentration or administration volume for the active preparations or saline. Each rat was brought to a simulated altitude of 11,500 m at 165 m/s at baseline and on days 7, 14 and 21. The primary endpoint was time to agonal breathing. The paper defines first collapse and posture recovery but does not tabulate those endpoints. Blood was collected the day after the final test. Behavior was recorded over 30 minutes at baseline and day 21.
Dose, route and schedule
Pep-1 through Pep-12 or saline was administered rectally once daily for 21 days. The article gives no dose, concentration or administration volume for the active preparations or saline.
Protocol source ↗ · Original methods, printed pp. 7–8
| Measure | Result | Comparison, timing and statistics |
|---|---|---|
| Pep-8 time to agonal breathing | 95 ± 12.5 to 655 ± 127.5 seconds | Printed day-21 coefficient 6.89×. Table 1 uses 95 ± 12.5 seconds as the baseline for all six arms in the second series. · Baseline to day 21 |
| Pep-8 horizontal activity and immobility | Activity 7% to 22%; immobility 52% to 21% | Saline control activity rose from 13% to 16% and immobility fell from 45% to 40%. · Baseline to day 21 |
| Highest day-21 times in each series | Pep-6, 787 ± 413 s; Pep-12, 659 ± 67.8 s | Pep-8 and Pep-11 were close to Pep-12. The paper gives no between-arm significance tests. |
| Arms with lower day-21 than day-14 times | Pep-7, 187 to 170 s; Pep-9, 478 to 315 s; Pep-10, 363 to 280 s | Reported means from Table 1. |
| Pep-8 blood measurements after the course | Lactate 18.6 vs 19.2; hemoglobin 178 vs 180 g/L | Pep-8 versus saline. The lactate column omits its unit. |
Table 1 · Time to agonal breathing at simulated altitude
| Arm | n | Baseline (s) | Day 7 (s) | Day 14 (s) | Day 21 (s) | Printed coefficients, days 7 / 14 / 21 |
|---|---|---|---|---|---|---|
| Pep-1 | 6 | 110 ± 65 | 250 ± 113 | 268 ± 204 | 435 ± 163 | 2.27 / 2.44 / 3.95 |
| Pep-2 | 6 | 110 ± 65 | 210 ± 110 | 348 ± 244 | 470 ± 180 | 1.91 / 3.16 / 4.27 |
| Pep-3 | 6 | 110 ± 65 | 315 ± 70 | 444 ± 154 | 515 ± 153 | 2.86 / 4.04 / 4.68 |
| Pep-4 | 6 | 110 ± 65 | 280 ± 267 | 403 ± 241 | 740 ± 323 | 3.45 / 3.66 / 6.73 |
| Pep-5 | 6 | 110 ± 65 | 320 ± 97 | 508 ± 185 | 742 ± 222 | 2.91 / 4.62 / 6.75 |
| Pep-6 | 6 | 110 ± 65 | 348 ± 244 | 370 ± 270 | 787 ± 413 | 3.16 / 3.36 / 7.15 |
| Pep-7 | 6 | 95 ± 12.5 | 135 ± 150.0 | 187 ± 71.3 | 170 ± 95.0 | 1.42 / 1.97 / 1.79 |
| Pep-8 | 6 | 95 ± 12.5 | 183 ± 83.0 | 533 ± 213.8 | 655 ± 127.5 | 1.91 / 5.60 / 6.89 |
| Pep-9 | 6 | 95 ± 12.5 | 390 ± 79.0 | 478 ± 98.8 | 315 ± 195.0 | 4.10 / 5.02 / 3.31 |
| Pep-10 | 6 | 95 ± 12.5 | 175 ± 127.5 | 363 ± 214.4 | 280 ± 126.7 | 1.84 / 3.82 / 2.95 |
| Pep-11 | 6 | 95 ± 12.5 | 214 ± 223.1 | 477 ± 262.5 | 650 ± 150.0 | 2.25 / 5.02 / 6.84 |
| Pep-12 | 6 | 95 ± 12.5 | 307 ± 69.8 | 543 ± 101.3 | 659 ± 67.8 | 3.23 / 5.70 / 6.94 |
| Saline control | 6 | Unlisted | Unlisted | Unlisted | Unlisted | Unlisted |
The methods give the group sizes and rectal schedule. The dose amount is unavailable for every arm. Time values and coefficients are reproduced as printed. For Pep-4 on day 7, 280 ÷ 110 is about 2.55, whereas the printed coefficient is 3.45. The saline row marks missing results and was added for clarity.
Table 2 · Blood chemistry after the course
| Arm | Urea | Glucose | Lactate | Triglycerides |
|---|---|---|---|---|
| Saline control | 320.4 ± 3.1 | 5.28 ± 0.15 | 19.2 ± 2.6 | 70 ± 4.1 |
| Pep-1 | 318.5 ± 2.9 | 5.30 ± 0.16 | 20.5 ± 3.2 | 73 ± 4.5 |
| Pep-2 | 325.7 ± 3.2 | 5.29 ± 0.16 | 21.0 ± 3.6 | 75 ± 4.7 |
| Pep-3 | 330.1 ± 4.4 | 5.31 ± 0.18 | 19.8 ± 2.9 | 73 ± 4.5 |
| Pep-4 | 322.0 ± 3.5 | 5.30 ± 0.17 | 19.5 ± 2.7 | 69 ± 3.9 |
| Pep-5 | 316.4 ± 2.8 | 5.33 ± 0.20 | 17.5 ± 1.7 | 65 ± 3.5 |
| Pep-6 | 315.1 ± 2.3 | 5.34 ± 0.22 | 17.8 ± 1.9 | 64 ± 3.4 |
| Pep-7 | 324.5 ± 3.7 | 5.31 ± 0.19 | 19.9 ± 3.0 | 71 ± 4.3 |
| Pep-8 | 319.9 ± 3.0 | 5.35 ± 0.24 | 18.6 ± 2.2 | 67 ± 3.6 |
| Pep-9 | 321.7 ± 3.2 | 5.29 ± 0.16 | 20.3 ± 2.3 | 72 ± 4.3 |
| Pep-10 | 322.8 ± 3.3 | 5.28 ± 0.15 | 21.1 ± 3.5 | 70 ± 4.1 |
| Pep-11 | 317.3 ± 2.7 | 5.34 ± 0.22 | 17.9 ± 1.9 | 66 ± 3.6 |
| Pep-12 | 318.9 ± 2.9 | 5.32 ± 0.21 | 18.7 ± 2.2 | 68 ± 3.7 |
The authors give no units for these four columns. They also give no pretreatment blood values or between-arm significance tests.
Table 3 · Blood counts after the course
| Arm | Red cells (10¹²/L) | Hemoglobin (g/L) | Hematocrit (%) |
|---|---|---|---|
| Saline control | 10.2 ± 0.60 | 180 ± 10 | 51.4 ± 4.8 |
| Pep-1 | 10.1 ± 0.58 | 180 ± 10 | 51.2 ± 4.6 |
| Pep-2 | 9.8 ± 0.56 | 179 ± 9 | 51.3 ± 4.7 |
| Pep-3 | 10.0 ± 0.57 | 178 ± 8 | 51.5 ± 4.9 |
| Pep-4 | 9.9 ± 0.56 | 181 ± 11 | 51.4 ± 4.7 |
| Pep-5 | 9.5 ± 0.50 | 180 ± 12 | 50.8 ± 4.3 |
| Pep-6 | 9.4 ± 0.49 | 179 ± 9 | 50.6 ± 4.2 |
| Pep-7 | 10.3 ± 0.61 | 182 ± 13 | 51.0 ± 4.5 |
| Pep-8 | 9.8 ± 0.58 | 178 ± 8 | 50.7 ± 4.4 |
| Pep-9 | 10.4 ± 0.62 | 184 ± 17 | 51.5 ± 4.9 |
| Pep-10 | 10.1 ± 0.58 | 181 ± 12 | 51.7 ± 5.0 |
| Pep-11 | 10.0 ± 0.57 | 179 ± 9 | 50.8 ± 4.3 |
| Pep-12 | 9.8 ± 0.58 | 183 ± 15 | 50.9 ± 4.4 |
Table 4 · Behavior at baseline and day 21
| Arm | Immobility (%) | Horizontal activity (%) | Grooming (%) |
|---|---|---|---|
| Saline control | 45 → 40 | 13 → 16 | 19 → 22 |
| Pep-1 | 30 → 19 | 11 → 25 | 18 → 21 |
| Pep-2 | 32 → 14 | 16 → 24 | 18 → 23 |
| Pep-3 | 36 → 29 | 13 → 22 | 17 → 19 |
| Pep-4 | 49 → 26 | 9 → 24 | 20 → 20 |
| Pep-5 | 57 → 35 | 6 → 22 | 11 → 15 |
| Pep-6 | 41 → 20 | 4 → 23 | 18 → 23 |
| Pep-7 | 44 → 33 | 12 → 24 | 18 → 19 |
| Pep-8 | 52 → 21 | 7 → 22 | 24 → 28 |
| Pep-9 | 26 → 17 | 14 → 26 | 9 → 23 |
| Pep-10 | 23 → 18 | 11 → 24 | 14 → 25 |
| Pep-11 | 49 → 28 | 5 → 23 | 20 → 24 |
| Pep-12 | 55 → 26 | 4 → 22 | 15 → 21 |
Percentages of the 30-minute observation session. The paper gives no uncertainty terms or arm-level significance tests for behavior.
The printed coefficients describe changes relative to the displayed series baselines. The missing saline hypoxia results and unclear baseline pooling prevent estimation of a saline-adjusted effect. The study does not establish operational performance or human safety.
Source for these results ↗ · Reviewed 2026-11-11
For research and education. Consult a qualified clinician for medical advice.
Study limitations and source details
Study limitations
- Table 1 repeats one baseline across Pep-1–6 and another across Pep-7–12. The paper gives no saline hypoxia trajectory and does not specify whether the series shared a control group. The printed coefficients are baseline-relative.
- The tables do not define the ± term or report arm-level statistical tests. The Pep-4 day-7 coefficient differs materially from the ratio of the printed means.
- Blood and behavior measurements do not establish muscle growth, long-term safety or human performance effects.
- The names Pep-8, Pept-8 and VIR-8 identify different records. Chemical equivalence remains unverified.
Source access
Archived publisher issue, printed pp. 6–15. Methods and Tables 1–4 checked against the page images.
Source reviewed 2026-11-11.
Citation and original source
Original source: N. N. Karkishchenko, V. N. Karkishchenko, Kh. Kh. Semenov, G. D. Kapanadze, Yu. V. Fokin, O. V. Alimkina, A. O. Revyakin, O. I. Stepanova, E. L. Matveyenko, N. V. Kasinskaya, S. E. Dengina. Animal-derived peptide preparations in rat hypoxia, behavior and blood studies Biomeditsina. 2013;(1):6–15. 2013.
Molekul research summary: https://molekul.io/research/pep-series-hypoxia-2013. Cite the original publication for its findings and this page when referring to Molekul’s summary or evidence appraisal.
Bibliography entry