How Glucocorticoid Patterns Change With Enteral Feeding Options During Chemotherapy in Rats

2.50
Hdl Handle:
http://hdl.handle.net/10755/165527
Category:
Abstract
Type:
Presentation
Title:
How Glucocorticoid Patterns Change With Enteral Feeding Options During Chemotherapy in Rats
Author(s):
Westfall, Una
Author Details:
Una Westfall, PhD, Professor, Oregon Health & Science University, School of Nursing, Portland, Oregon, USA, email: westfall@ohsu.edu
Abstract:
Nutritional intake is a major challenge for cancer patients. When nutrition can't be taken orally and the gut is intact, enteral feedings are an option. A chronobiology framework supports examining temporal patterns and timing of interventions. Well-established circadian glucocorticoid patterns, peaking around activity onset, are linked with daily activities, health, and metabolism. Nutritional studies report altered glucocorticoid patterns, but examining too few variables has led to confusing findings. To help oncology nurses make evidenced-based enteral feeding decisions, we tested for the presence and characteristics of circadian corticosterone rhythms with two enteral feeding schedules (12/24 hour), delivered by two methods (pump/bolus), using two fiber levels (hi/no), at two kilocalorie (kcal) levels (80/55 kcal/day), in an animal model receiving 5-fluorouracil (5-FU). A 2 x 2 x 2 x 2 randomized block design was used with male Sprague-Dawley rats, (n = -80/[5/cell]), who received intraperitoneal 5-FU, 50mg/kg. Rat housing was an approved animal care facility with a 12 hr. on/12 hr. off lighting cycle. Rats had standard 28-day protocols with gastrostomy tubes placed when body weights were > = 170 gms (~Day 7). Following acclimation, enteral feedings were days 18-28. IP 5-FU was given on day 22. Twenty-four hourly blood samples were drawn on days 26-28 from each feeding group. Plasma corticosterone levels were measured in duplicate using 125 I radioimmuno assays, with coefficients of variation less than 3.0%. Using plasma levels, a "composite" animal was constructed for each group. A circadian rhythm of corticosterone was present (p < .05) or suggested (p > .05 < .10) using cosinor analysis in only nine of 16 enterally fed groups: seven of the eight 24-hour schedule groups; two of the 12-hour schedule groups. Compared with hi-fiber groups, midpoint levels were higher by 0.9-4.1µg/dl in the 24-hour, no-fiber groups. Calculated peak times in the 24-hour groups were delayed from activity onset time by 99 to 336 minutes; in the two 12-hour groups, peak times were within 17 minutes of activity onset time. Greater glucocorticoid pattern disruptions occurred with 12-hour feedings. When glucocorticoid rhythms were present in the 24-hour schedule groups, peak times were delayed. These disruptions or shifts of expected circadian corticosterone patterns suggest that those receiving 5-FU and enteral feedings may find some enteral feeding options more problematic than others.
Repository Posting Date:
27-Oct-2011
Date of Publication:
27-Oct-2011
Conference Date:
2002
Conference Name:
27th Annual Oncology Nursing Society Congress
Conference Host:
Oncology Nursing Society
Conference Location:
Washington, D.C., USA
Note:
This is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.

Full metadata record

DC FieldValue Language
dc.type.categoryAbstracten_US
dc.typePresentationen_GB
dc.titleHow Glucocorticoid Patterns Change With Enteral Feeding Options During Chemotherapy in Ratsen_GB
dc.contributor.authorWestfall, Unaen_US
dc.author.detailsUna Westfall, PhD, Professor, Oregon Health & Science University, School of Nursing, Portland, Oregon, USA, email: westfall@ohsu.eduen_US
dc.identifier.urihttp://hdl.handle.net/10755/165527-
dc.description.abstractNutritional intake is a major challenge for cancer patients. When nutrition can't be taken orally and the gut is intact, enteral feedings are an option. A chronobiology framework supports examining temporal patterns and timing of interventions. Well-established circadian glucocorticoid patterns, peaking around activity onset, are linked with daily activities, health, and metabolism. Nutritional studies report altered glucocorticoid patterns, but examining too few variables has led to confusing findings. To help oncology nurses make evidenced-based enteral feeding decisions, we tested for the presence and characteristics of circadian corticosterone rhythms with two enteral feeding schedules (12/24 hour), delivered by two methods (pump/bolus), using two fiber levels (hi/no), at two kilocalorie (kcal) levels (80/55 kcal/day), in an animal model receiving 5-fluorouracil (5-FU). A 2 x 2 x 2 x 2 randomized block design was used with male Sprague-Dawley rats, (n = -80/[5/cell]), who received intraperitoneal 5-FU, 50mg/kg. Rat housing was an approved animal care facility with a 12 hr. on/12 hr. off lighting cycle. Rats had standard 28-day protocols with gastrostomy tubes placed when body weights were &gt; = 170 gms (~Day 7). Following acclimation, enteral feedings were days 18-28. IP 5-FU was given on day 22. Twenty-four hourly blood samples were drawn on days 26-28 from each feeding group. Plasma corticosterone levels were measured in duplicate using 125 I radioimmuno assays, with coefficients of variation less than 3.0%. Using plasma levels, a &quot;composite&quot; animal was constructed for each group. A circadian rhythm of corticosterone was present (p &lt; .05) or suggested (p &gt; .05 &lt; .10) using cosinor analysis in only nine of 16 enterally fed groups: seven of the eight 24-hour schedule groups; two of the 12-hour schedule groups. Compared with hi-fiber groups, midpoint levels were higher by 0.9-4.1&micro;g/dl in the 24-hour, no-fiber groups. Calculated peak times in the 24-hour groups were delayed from activity onset time by 99 to 336 minutes; in the two 12-hour groups, peak times were within 17 minutes of activity onset time. Greater glucocorticoid pattern disruptions occurred with 12-hour feedings. When glucocorticoid rhythms were present in the 24-hour schedule groups, peak times were delayed. These disruptions or shifts of expected circadian corticosterone patterns suggest that those receiving 5-FU and enteral feedings may find some enteral feeding options more problematic than others.en_GB
dc.date.available2011-10-27T12:20:15Z-
dc.date.issued2011-10-27en_GB
dc.date.accessioned2011-10-27T12:20:15Z-
dc.conference.date2002en_US
dc.conference.name27th Annual Oncology Nursing Society Congressen_US
dc.conference.hostOncology Nursing Societyen_US
dc.conference.locationWashington, D.C., USAen_US
dc.description.noteThis is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission. Alternatively, please contact the conference host, journal, or publisher (according to the circumstance) for further details regarding this item. If a citation is listed in this record, the item has been published and is available via open-access avenues or a journal/database subscription. Contact your library for assistance in obtaining the as-published article.-
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